View Poll Results: RWD or AWD?
RWD
15
46.88%
AWD
17
53.13%
Voters: 32. You may not vote on this poll
All else equal: RWD or AWD?
#161
Banned
Purpose of LSD is the same as AWD; to limit the loss of traction. And I owned an AWD car with a locking diff. Mind blown?
#162
Ex-OEM King
#163
Team Owner
And for the record, you are incredibly wrong. An LSD does not help in the way you are suggesting. I have one in my car and it never ever helps in getting going from a standing stop, if the ground is sloppy or icy. It just doesn't. The car behaves like any other non-lsd fwd car. I'm not sure why you are having a hard time understanding this. No one is trying to mislead you here.
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#164
Safety Car
Couple of different concepts being thrown around here. This might not be super technical, but generally here are the various different things discussed to get us all on the same page:
Differential - A gearset required to allow different wheels on the same axle to spin at different rates. Because all 4 wheels on a car will take different paths while driving around, they will be required to turn at different rates in respect to one another. The drive wheels (front, rear, or all) need to be able to get the power together, but apportion the power differently as necessary.
Open Differential (or standard or unlocked) - The default differential. The design of this differential will distribute the same torque to each wheel on the axle. This also means that if one wheel does not have any traction at all, the other wheel will get negligible power and the end result is there is no forward travel of the vehicle. This is because the wheel without traction will spin very easily, getting very little torque but high spin. The open differential distributes the same amount of torque to the other wheel.
Limited Slip Differential - The differential, through different techniques, will not allow the above scenario to happen. As one wheel slips, the differential limits the slip (hence the name) and transfers this power to the slower moving wheel. This preserves some forward movement ability even if one wheel is slipping. This can also be accomplished electronically by individually actuating the brake of the slipping wheel. The slipping wheel now takes more power to turn (due to the brake being applied) and the open differential then gives more power to the other wheel.
The reason why LSDs are found on a Civic Si or TL 6MT is because those are performance biased front wheel drive cars. By its nature, FWD cars lose drive wheel grip more easily than RWD. Now that RWD cars no longer have solid beam rear axles, they tend to maintain traction over their rear wheels easier than FWD cars. Performance oriented RWD cars will also have LSD as standard or an option, but it it is not as important to them as in the FWD unless you're doing some VERY spirited driving (like a track). For commuter level cars, the more common thing now is to implement a brake LSD type thing.
All-Wheel Drive - There is a center differential that apportions power between the front and the rear wheels as necessary. Much like the differential discussion above, there are different ways to apportion the power. I don't think anybody uses a simple open differential to split power between the front and rear axles because that would be useless. Instead, there's going to be various forms of what is essentially a limited slip differential that is splitting power between the front and rear axles as needed. Some cars are usually FWD and send power to the rear during slip (cheaper to build on a front engine car), and then some cars are RWD and send power to the front in slip. This is what's called the "front" or "rear" bias.
On more sophisticated systems, there may also be limited slip differentials between each wheel on each axle. What this means is not only can power be sent front or rear as needed, it can also be sent side to side as needed. This is what the mechanical version of SH-AWD did.
Locking differential - A differential that can be locked to move as one unit. Power will be split regardless of wheel spin. This is a problem if used on road so this is reserved for off-road vehicles. A locking differential can be found at the center differential and/or one or both of the axles. In other words, a center locking diff will send power 50/50 F/R and then some cars have a rear locking diff that will send the power 50/50 L/R. And then there are some that have a front locking diff too (Jeeps, Humvees, other hardcore offroaders).
Nowhere is all of this stuff more apparent than when you go off-roading (or I suppose driving in snow).
2WD car (FWD, RWD doesn't matter) with open differential - If any one of the two drive tires slip, no forward movement of the car.
AWD with open differentials on the axles - If any one of the main drive tires slip, power is sent to the other axle. If any one of those slip too, there is no forward movement of the car.
4WD with locked center differential - Power is sent 50/50 to the front and rear axles regardless of slip. If any one tire slips on each axle, there is no forward movement of the car.
4WD with "locking differential" - This actually means one or both of the axles also have a locking differential. So power is sent 50/50 to F and R, and then if "locked" power is additionally split 50/50 L and R. So as long as a single tire on the locked axle gets grip, the car can continue to move forward.
Differential - A gearset required to allow different wheels on the same axle to spin at different rates. Because all 4 wheels on a car will take different paths while driving around, they will be required to turn at different rates in respect to one another. The drive wheels (front, rear, or all) need to be able to get the power together, but apportion the power differently as necessary.
Open Differential (or standard or unlocked) - The default differential. The design of this differential will distribute the same torque to each wheel on the axle. This also means that if one wheel does not have any traction at all, the other wheel will get negligible power and the end result is there is no forward travel of the vehicle. This is because the wheel without traction will spin very easily, getting very little torque but high spin. The open differential distributes the same amount of torque to the other wheel.
Limited Slip Differential - The differential, through different techniques, will not allow the above scenario to happen. As one wheel slips, the differential limits the slip (hence the name) and transfers this power to the slower moving wheel. This preserves some forward movement ability even if one wheel is slipping. This can also be accomplished electronically by individually actuating the brake of the slipping wheel. The slipping wheel now takes more power to turn (due to the brake being applied) and the open differential then gives more power to the other wheel.
The reason why LSDs are found on a Civic Si or TL 6MT is because those are performance biased front wheel drive cars. By its nature, FWD cars lose drive wheel grip more easily than RWD. Now that RWD cars no longer have solid beam rear axles, they tend to maintain traction over their rear wheels easier than FWD cars. Performance oriented RWD cars will also have LSD as standard or an option, but it it is not as important to them as in the FWD unless you're doing some VERY spirited driving (like a track). For commuter level cars, the more common thing now is to implement a brake LSD type thing.
All-Wheel Drive - There is a center differential that apportions power between the front and the rear wheels as necessary. Much like the differential discussion above, there are different ways to apportion the power. I don't think anybody uses a simple open differential to split power between the front and rear axles because that would be useless. Instead, there's going to be various forms of what is essentially a limited slip differential that is splitting power between the front and rear axles as needed. Some cars are usually FWD and send power to the rear during slip (cheaper to build on a front engine car), and then some cars are RWD and send power to the front in slip. This is what's called the "front" or "rear" bias.
On more sophisticated systems, there may also be limited slip differentials between each wheel on each axle. What this means is not only can power be sent front or rear as needed, it can also be sent side to side as needed. This is what the mechanical version of SH-AWD did.
Locking differential - A differential that can be locked to move as one unit. Power will be split regardless of wheel spin. This is a problem if used on road so this is reserved for off-road vehicles. A locking differential can be found at the center differential and/or one or both of the axles. In other words, a center locking diff will send power 50/50 F/R and then some cars have a rear locking diff that will send the power 50/50 L/R. And then there are some that have a front locking diff too (Jeeps, Humvees, other hardcore offroaders).
Nowhere is all of this stuff more apparent than when you go off-roading (or I suppose driving in snow).
2WD car (FWD, RWD doesn't matter) with open differential - If any one of the two drive tires slip, no forward movement of the car.
AWD with open differentials on the axles - If any one of the main drive tires slip, power is sent to the other axle. If any one of those slip too, there is no forward movement of the car.
4WD with locked center differential - Power is sent 50/50 to the front and rear axles regardless of slip. If any one tire slips on each axle, there is no forward movement of the car.
4WD with "locking differential" - This actually means one or both of the axles also have a locking differential. So power is sent 50/50 to F and R, and then if "locked" power is additionally split 50/50 L and R. So as long as a single tire on the locked axle gets grip, the car can continue to move forward.
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#165
Safety Car
Before somebody jumps in to correct me, technically a 4WD vehicle has a transfer case and not a differential. But for me it has been easier to visualize and explain the concepts if you think of them in the same vein as differentials.
#166
Safety Car
Second addition - Apparently some companies do use an open center differential in AWD applications but then compensate for this inherent uselessness by throwing in electronic brake "limited slip."
The reason is cost. This would be the cheapest and mechanically simplest way to get AWD.
The reason is cost. This would be the cheapest and mechanically simplest way to get AWD.
#167
Climbing that hill in a SUBARU WITH ALL SEASONS.... I passed a row of 30+ FWD/RWD cars that were all on the side trying to go up.... tell me again how RWD is better in the snow?
AWD provides MORE TRACTIVE EFFORT AS IT CAN USE ALL 4 WHEELS to move the car forward instead of 2 at the front of rear of the car...
Last edited by YeuEmMaiMai; 02-15-2018 at 11:30 AM.
#168
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please put down the crack pipe....you have no idea what you are talking about....
Climbing that hill in a SUBARU WITH ALL SEASONS.... I passed a row of 30+ FWD/RWD cars that were all on the side trying to go up.... tell me again how RWD is better in the snow?
AWD provides MORE TRACTIVE EFFORT AS IT CAN USE ALL 4 WHEELS to move the car forward instead of 2 at the front of rear of the car...
Climbing that hill in a SUBARU WITH ALL SEASONS.... I passed a row of 30+ FWD/RWD cars that were all on the side trying to go up.... tell me again how RWD is better in the snow?
AWD provides MORE TRACTIVE EFFORT AS IT CAN USE ALL 4 WHEELS to move the car forward instead of 2 at the front of rear of the car...
Maybe you're the one who needs to put the crack pipe down.
#169
Ex-OEM King
Second addition - Apparently some companies do use an open center differential in AWD applications but then compensate for this inherent uselessness by throwing in electronic brake "limited slip."
The reason is cost. This would be the cheapest and mechanically simplest way to get AWD.
The reason is cost. This would be the cheapest and mechanically simplest way to get AWD.
To recap:
- RWD is better than AWD!
- Except for in the snow
- And for acceleration
- And for handling
- Doesn't make a difference for braking
#170
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Incorrect, you said I said that, I didn't. Please stop putting words in my mouth, either that or quote the post where I stated RWD was superior in all aspects to AWD.
#171
uhh, is that the best retort you got? for a minute there I thought I was going to get a well thought out reply....not.. There is absolutely no scenario where RWD is better in the snow, all other things being equal
Last edited by YeuEmMaiMai; 02-15-2018 at 02:35 PM.
#172
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The other most common area where a RWD car will out perform an AWD car is when rounding a bend while climbing a grade; if you understand the "friction circle" concept (posted above) you'll see every ounce of forward tractive energy put into the front wheels will cause a commensurate reduction in lateral grip.
Last edited by horseshoez; 02-15-2018 at 02:45 PM.
#173
Moderator
please put down the crack pipe....you have no idea what you are talking about....
Climbing that hill in a SUBARU WITH ALL SEASONS.... I passed a row of 30+ FWD/RWD cars that were all on the side trying to go up.... tell me again how RWD is better in the snow?
AWD provides MORE TRACTIVE EFFORT AS IT CAN USE ALL 4 WHEELS to move the car forward instead of 2 at the front of rear of the car...
Climbing that hill in a SUBARU WITH ALL SEASONS.... I passed a row of 30+ FWD/RWD cars that were all on the side trying to go up.... tell me again how RWD is better in the snow?
AWD provides MORE TRACTIVE EFFORT AS IT CAN USE ALL 4 WHEELS to move the car forward instead of 2 at the front of rear of the car...
Well then you really don't understand physics. In an "all else being equal" scenario, there is no question a lighter RWD car (say 330i vs. 330xi) will stop shorter in slippery conditions; simple physics.
The other most common area where a RWD car will out perform an AWD car is when rounding a bend while climbing a grade; if you understand the "friction circle" concept (posted above) you'll see every ounce of forward tractive energy put into the front wheels will cause a commensurate reduction in lateral grip.
The other most common area where a RWD car will out perform an AWD car is when rounding a bend while climbing a grade; if you understand the "friction circle" concept (posted above) you'll see every ounce of forward tractive energy put into the front wheels will cause a commensurate reduction in lateral grip.
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#174
I drive a Subata.
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Seriously. Kids are acting like they are in junior high.
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#176
Moderator
#177
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horseshoez wins because of age. Everyone else stop trying to win.
#178
Well then you really don't understand physics. In an "all else being equal" scenario, there is no question a lighter RWD car (say 330i vs. 330xi) will stop shorter in slippery conditions; simple physics.
The other most common area where a RWD car will out perform an AWD car is when rounding a bend while climbing a grade; if you understand the "friction circle" concept (posted above) you'll see every ounce of forward tractive energy put into the front wheels will cause a commensurate reduction in lateral grip.
The other most common area where a RWD car will out perform an AWD car is when rounding a bend while climbing a grade; if you understand the "friction circle" concept (posted above) you'll see every ounce of forward tractive energy put into the front wheels will cause a commensurate reduction in lateral grip.
Last edited by YeuEmMaiMai; 02-15-2018 at 06:03 PM.
#179
Someday, an RS6 Avant+
I never heard of an advantage braking with any type of drive. Braking is braking, unless you are letting the transmission do the braking, then AWD might slow you down a little bit more because the transmission regressive force is going to all four wheels. Now, saying a RWD car brakes better? Um, you'll have to produce some test results that show this (ie. cars with somewhat equal weight, weight distribution, and brake setup). The tyre type / contact patch and braking system plus the initial speed / road conditions are what set up your braking forces (along with vehicle weight dynamics.
I used to own an 84 Audi 5000S Wagon manual in southern Bavaria (actually Norther Austria. The weight distribution on that thing was horrible (40/60). And if anything was in the hatch, oh, boy. Winter driving in that car was a neat trick.
I'm not ancient, but I've lived a fairly long life in a lot of countries to have some experience. And FTR, I'd never drive in Russia. No f-#$%*&^ way.
I used to own an 84 Audi 5000S Wagon manual in southern Bavaria (actually Norther Austria. The weight distribution on that thing was horrible (40/60). And if anything was in the hatch, oh, boy. Winter driving in that car was a neat trick.
I'm not ancient, but I've lived a fairly long life in a lot of countries to have some experience. And FTR, I'd never drive in Russia. No f-#$%*&^ way.
Last edited by mrmako; 02-15-2018 at 06:23 PM.
#180
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You folks continue to miss the point; take two otherwise identical cars, but with one lighter than the other, the lighter car will ALWAYS stop shorter, all else being equal.
Consider the following:
Consider the following:
- 2018 BMW 330i -- 3,541 pounds
- 2018 BMW 330xi - 3,706 pounds -- 165 pounds heavier
- 2018 Mercedes-Benz C300 ---------- 3,417 pounds
- 2018 Mercedes-Benz C300 4MATIC - 3,594 pounds -- 177 pounds heavier
- 2018 Infiniti Q70 5.6 LUXE ------- 4,043 pounds
- 2018 Infiniti Q70 5.6 LUXE AWD - 4,239 pounds -- 196 pounds heavier
- 2018 Chrysler 300 Limited ------- 4,013 pounds
- 2018 Chrysler 300 Limited AWD - 4,267 pounds -- 254 pounds heavier
#181
Someday, an RS6 Avant+
This does not answer the braking question, but explains FWD/AWD/RWD pretty well:
https://www.digitaltrends.com/cars/fwd-vs-awd-vs-rwd/
https://www.digitaltrends.com/cars/fwd-vs-awd-vs-rwd/
#182
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This does not answer the braking question, but explains FWD/AWD/RWD pretty well:
https://www.digitaltrends.com/cars/fwd-vs-awd-vs-rwd/
https://www.digitaltrends.com/cars/fwd-vs-awd-vs-rwd/
"Honda’s long list of affordable performance models, with the exception of its NSX, have been built exclusively on front-wheel drive platforms."
Hmmm, maybe they've never heard of the S2000.
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mrmako (02-15-2018)
#183
Safety Car
First of all, a lot of these arguments I've been seeing are very clinical or academic. There's also been a lot of focus on snow driving, but that's not really relevant to 00TL who lives in Houston with me. I say clinical or academic because it has to do with paper statistics. Have you guys actually driven all of these different cars?
We've been saying RWD is more fun. Seems everybody, including myself, have been guilty of just kind of glossing over the basics but we haven't said why RWD is more fun. Legend2TL did provide some explanation, but I think we need something that covers the fundamentals and translates to real world experience for the uninitiated.
Right now in my driveway, I have FWD (Acura CL-S 6MT), RWD (Acura NSX, SL55 AMG), and AWD (911 Turbo). So I've driven them all. In plain words, this is how they are different.
Like I said previously, AWD helps manage power. Tires have a finite amount of grip. If you have RWD, you're splitting the power by half. If you have AWD, you're splitting the power 4 ways. Since tires can only generate so much grip, as power gets higher, having power split among more tires means that an individual tire doesn't get overwhelmed. The easier it is to overwhelm the tires, the more skill it takes to make sure the tires don't get overwhelmed and result in a total loss of control that the driver is not skilled enough to recover from. This is why high horsepower cars tend to have AWD.
The reason why RWD "is more fun" is because of rotation. When you go into a turn, you have to get the front facing where you want to go. This rate of turn is usually influenced by the steering wheel. But if you can get the rear tires to slide laterally a little, you can "rotate" the front of the car around quicker. In a RWD car, this can be accomplished by giving a little gas. The power overwhelms the rear tire's grip and they slide a little. This is called power induced oversteer. A little bit of of slide is called rotation. A lot of slide is drifting. This takes a bit of skill (and I'm not very good) but when you get it, it is thrilling. This is also not really reproducible on the street. Maybe on some back roads, but don't slide into the ditch!
With FWD, the technique to get around a turn quickly is different. You can't simply add power to step the rear out a little. The rears in a FWD car will almost always have more grip than the fronts so there's no rotation. Instead, the technique with FWD is to get a little bit of trail braking (because braking transfers weight to the front and presses down in the power wheels) and then power your way out of the turn. Point the car's front where you want to go and get on the throttle and have the front tires claw your car out of the turn (this is why FWD cars need an LSD. If either of the two tires lose grip, you're not going to go anywhere with an open diff).
With AWD, you're splitting the power to all wheels so it is a lot harder to overwhelm the tires. Driving AWD fast around turns is closer to FWD than it is to RWD. Go into turns a little hotter than with a RWD car and use weight transfer and some throttle to slide the rears and get some rotation (if you have a RWD biased system), and then nail the gas once your front is pointed where you want to go. The 4 tires will grab and push you out of the turn.
As you can see, FWD and AWD technique is more noob friendly. A lot of it is "point and squirt" whereas RWD takes more finesse. But in the hands of a better driver, being able to rotate the rear is going to get you around a turn faster than steering inputs alone. This is why the 911 Turbo is AWD and the GT3 is RWD.
We've been saying RWD is more fun. Seems everybody, including myself, have been guilty of just kind of glossing over the basics but we haven't said why RWD is more fun. Legend2TL did provide some explanation, but I think we need something that covers the fundamentals and translates to real world experience for the uninitiated.
Right now in my driveway, I have FWD (Acura CL-S 6MT), RWD (Acura NSX, SL55 AMG), and AWD (911 Turbo). So I've driven them all. In plain words, this is how they are different.
Like I said previously, AWD helps manage power. Tires have a finite amount of grip. If you have RWD, you're splitting the power by half. If you have AWD, you're splitting the power 4 ways. Since tires can only generate so much grip, as power gets higher, having power split among more tires means that an individual tire doesn't get overwhelmed. The easier it is to overwhelm the tires, the more skill it takes to make sure the tires don't get overwhelmed and result in a total loss of control that the driver is not skilled enough to recover from. This is why high horsepower cars tend to have AWD.
The reason why RWD "is more fun" is because of rotation. When you go into a turn, you have to get the front facing where you want to go. This rate of turn is usually influenced by the steering wheel. But if you can get the rear tires to slide laterally a little, you can "rotate" the front of the car around quicker. In a RWD car, this can be accomplished by giving a little gas. The power overwhelms the rear tire's grip and they slide a little. This is called power induced oversteer. A little bit of of slide is called rotation. A lot of slide is drifting. This takes a bit of skill (and I'm not very good) but when you get it, it is thrilling. This is also not really reproducible on the street. Maybe on some back roads, but don't slide into the ditch!
With FWD, the technique to get around a turn quickly is different. You can't simply add power to step the rear out a little. The rears in a FWD car will almost always have more grip than the fronts so there's no rotation. Instead, the technique with FWD is to get a little bit of trail braking (because braking transfers weight to the front and presses down in the power wheels) and then power your way out of the turn. Point the car's front where you want to go and get on the throttle and have the front tires claw your car out of the turn (this is why FWD cars need an LSD. If either of the two tires lose grip, you're not going to go anywhere with an open diff).
With AWD, you're splitting the power to all wheels so it is a lot harder to overwhelm the tires. Driving AWD fast around turns is closer to FWD than it is to RWD. Go into turns a little hotter than with a RWD car and use weight transfer and some throttle to slide the rears and get some rotation (if you have a RWD biased system), and then nail the gas once your front is pointed where you want to go. The 4 tires will grab and push you out of the turn.
As you can see, FWD and AWD technique is more noob friendly. A lot of it is "point and squirt" whereas RWD takes more finesse. But in the hands of a better driver, being able to rotate the rear is going to get you around a turn faster than steering inputs alone. This is why the 911 Turbo is AWD and the GT3 is RWD.
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#184
Someday, an RS6 Avant+
And what I found concerning snow braking:
https://www.youtube.com/watch?v=fMHSBXjiyac
https://www.youtube.com/watch?v=fMHSBXjiyac
Last edited by mrmako; 02-15-2018 at 08:26 PM. Reason: Fixed link
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#185
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#186
You folks continue to miss the point; take two otherwise identical cars, but with one lighter than the other, the lighter car will ALWAYS stop shorter, all else being equal.
Consider the following:
Consider the following:
- 2018 BMW 330i -- 3,541 pounds
- 2018 BMW 330xi - 3,706 pounds -- 165 pounds heavier
- 2018 Mercedes-Benz C300 ---------- 3,417 pounds
- 2018 Mercedes-Benz C300 4MATIC - 3,594 pounds -- 177 pounds heavier
- 2018 Infiniti Q70 5.6 LUXE ------- 4,043 pounds
- 2018 Infiniti Q70 5.6 LUXE AWD - 4,239 pounds -- 196 pounds heavier
- 2018 Chrysler 300 Limited ------- 4,013 pounds
- 2018 Chrysler 300 Limited AWD - 4,267 pounds -- 254 pounds heavier
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horseshoez (02-15-2018)
#187
Someday, an RS6 Avant+
#188
GEEZER
Kill me now.
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#189
Ex-OEM King
First of all, a lot of these arguments I've been seeing are very clinical or academic. There's also been a lot of focus on snow driving, but that's not really relevant to 00TL who lives in Houston with me. I say clinical or academic because it has to do with paper statistics. Have you guys actually driven all of these different cars?
We've been saying RWD is more fun. Seems everybody, including myself, have been guilty of just kind of glossing over the basics but we haven't said why RWD is more fun. Legend2TL did provide some explanation, but I think we need something that covers the fundamentals and translates to real world experience for the uninitiated.
Right now in my driveway, I have FWD (Acura CL-S 6MT), RWD (Acura NSX, SL55 AMG), and AWD (911 Turbo). So I've driven them all. In plain words, this is how they are different.
Like I said previously, AWD helps manage power. Tires have a finite amount of grip. If you have RWD, you're splitting the power by half. If you have AWD, you're splitting the power 4 ways. Since tires can only generate so much grip, as power gets higher, having power split among more tires means that an individual tire doesn't get overwhelmed. The easier it is to overwhelm the tires, the more skill it takes to make sure the tires don't get overwhelmed and result in a total loss of control that the driver is not skilled enough to recover from. This is why high horsepower cars tend to have AWD.
The reason why RWD "is more fun" is because of rotation. When you go into a turn, you have to get the front facing where you want to go. This rate of turn is usually influenced by the steering wheel. But if you can get the rear tires to slide laterally a little, you can "rotate" the front of the car around quicker. In a RWD car, this can be accomplished by giving a little gas. The power overwhelms the rear tire's grip and they slide a little. This is called power induced oversteer. A little bit of of slide is called rotation. A lot of slide is drifting. This takes a bit of skill (and I'm not very good) but when you get it, it is thrilling. This is also not really reproducible on the street. Maybe on some back roads, but don't slide into the ditch!
Kind of... Yes you're right about rotation but a RWD car will rotate on its own without power oversteer. The reason is because tires want to go in a straight line no matter what. This is why the wheels have to turn and you don't slide around uncontrollably as you drive. Because the rear wheels don't turn, they create a moment about the pivot point (which is the tire patch of the front wheels) and when you nail the gas, it forces the car to pivot around that point regardless of wheel slip. The LSD is needed here because of weight transfer in turns causing the inside wheel to lift a bit during power corner exit and start spinning. It happens quite a lot on high HP and stiff performance cars and the LSD mitigates that issue.
With FWD, the technique to get around a turn quickly is different. You can't simply add power to step the rear out a little. The rears in a FWD car will almost always have more grip than the fronts so there's no rotation. Instead, the technique with FWD is to get a little bit of trail braking (because braking transfers weight to the front and presses down in the power wheels) and then power your way out of the turn. Point the car's front where you want to go and get on the throttle and have the front tires claw your car out of the turn (this is why FWD cars need an LSD. If either of the two tires lose grip, you're not going to go anywhere with an open diff).
With AWD, you're splitting the power to all wheels so it is a lot harder to overwhelm the tires. Driving AWD fast around turns is closer to FWD than it is to RWD. Go into turns a little hotter than with a RWD car and use weight transfer and some throttle to slide the rears and get some rotation (if you have a RWD biased system), and then nail the gas once your front is pointed where you want to go. The 4 tires will grab and push you out of the turn.
This is why many AWD performance cars are RWD biased. Also, the same effect as the RWD portion applies so you don't necessarily need to overwhelm the tires to make something happen.
As you can see, FWD and AWD technique is more noob friendly. A lot of it is "point and squirt" whereas RWD takes more finesse. But in the hands of a better driver, being able to rotate the rear is going to get you around a turn faster than steering inputs alone. This is why the 911 Turbo is AWD and the GT3 is RWD.
We've been saying RWD is more fun. Seems everybody, including myself, have been guilty of just kind of glossing over the basics but we haven't said why RWD is more fun. Legend2TL did provide some explanation, but I think we need something that covers the fundamentals and translates to real world experience for the uninitiated.
Right now in my driveway, I have FWD (Acura CL-S 6MT), RWD (Acura NSX, SL55 AMG), and AWD (911 Turbo). So I've driven them all. In plain words, this is how they are different.
Like I said previously, AWD helps manage power. Tires have a finite amount of grip. If you have RWD, you're splitting the power by half. If you have AWD, you're splitting the power 4 ways. Since tires can only generate so much grip, as power gets higher, having power split among more tires means that an individual tire doesn't get overwhelmed. The easier it is to overwhelm the tires, the more skill it takes to make sure the tires don't get overwhelmed and result in a total loss of control that the driver is not skilled enough to recover from. This is why high horsepower cars tend to have AWD.
The reason why RWD "is more fun" is because of rotation. When you go into a turn, you have to get the front facing where you want to go. This rate of turn is usually influenced by the steering wheel. But if you can get the rear tires to slide laterally a little, you can "rotate" the front of the car around quicker. In a RWD car, this can be accomplished by giving a little gas. The power overwhelms the rear tire's grip and they slide a little. This is called power induced oversteer. A little bit of of slide is called rotation. A lot of slide is drifting. This takes a bit of skill (and I'm not very good) but when you get it, it is thrilling. This is also not really reproducible on the street. Maybe on some back roads, but don't slide into the ditch!
Kind of... Yes you're right about rotation but a RWD car will rotate on its own without power oversteer. The reason is because tires want to go in a straight line no matter what. This is why the wheels have to turn and you don't slide around uncontrollably as you drive. Because the rear wheels don't turn, they create a moment about the pivot point (which is the tire patch of the front wheels) and when you nail the gas, it forces the car to pivot around that point regardless of wheel slip. The LSD is needed here because of weight transfer in turns causing the inside wheel to lift a bit during power corner exit and start spinning. It happens quite a lot on high HP and stiff performance cars and the LSD mitigates that issue.
With FWD, the technique to get around a turn quickly is different. You can't simply add power to step the rear out a little. The rears in a FWD car will almost always have more grip than the fronts so there's no rotation. Instead, the technique with FWD is to get a little bit of trail braking (because braking transfers weight to the front and presses down in the power wheels) and then power your way out of the turn. Point the car's front where you want to go and get on the throttle and have the front tires claw your car out of the turn (this is why FWD cars need an LSD. If either of the two tires lose grip, you're not going to go anywhere with an open diff).
With AWD, you're splitting the power to all wheels so it is a lot harder to overwhelm the tires. Driving AWD fast around turns is closer to FWD than it is to RWD. Go into turns a little hotter than with a RWD car and use weight transfer and some throttle to slide the rears and get some rotation (if you have a RWD biased system), and then nail the gas once your front is pointed where you want to go. The 4 tires will grab and push you out of the turn.
This is why many AWD performance cars are RWD biased. Also, the same effect as the RWD portion applies so you don't necessarily need to overwhelm the tires to make something happen.
As you can see, FWD and AWD technique is more noob friendly. A lot of it is "point and squirt" whereas RWD takes more finesse. But in the hands of a better driver, being able to rotate the rear is going to get you around a turn faster than steering inputs alone. This is why the 911 Turbo is AWD and the GT3 is RWD.
Guys I disagree with a lot of what he said in this thread. However he’s 100% right about the braking in RWD vs AWD. Everything equal (same car, same road, same tires, same brakes, same options, same speed) the lighter RWD car (ASSUMING the RWD car would be lighter because AWD adds weight) will stop sooner. Think about it, less mass with the same brake force results in quicker braking. There is no 2 ways about that. Whether ~200 pounds equates to a massive difference or not, even 0.1” quicker stopping is still quicker stopping and I think it’s false to think a heavier vehicle would stop just as well as a lighter vehicle. That defies physics.
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#193
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You folks continue to miss the point; take two otherwise identical cars, but with one lighter than the other, the lighter car will ALWAYS stop shorter, all else being equal.
Consider the following:
Consider the following:
- 2018 BMW 330i -- 3,541 pounds
- 2018 BMW 330xi - 3,706 pounds -- 165 pounds heavier
- 2018 Mercedes-Benz C300 ---------- 3,417 pounds
- 2018 Mercedes-Benz C300 4MATIC - 3,594 pounds -- 177 pounds heavier
- 2018 Infiniti Q70 5.6 LUXE ------- 4,043 pounds
- 2018 Infiniti Q70 5.6 LUXE AWD - 4,239 pounds -- 196 pounds heavier
- 2018 Chrysler 300 Limited ------- 4,013 pounds
- 2018 Chrysler 300 Limited AWD - 4,267 pounds -- 254 pounds heavier
Either way... sure... you win. a RWD may marginally brake better than an AWD car... under certain conditions. I really wonder if anyone would actually notice the 4 feet they would stop sooner, or not.... unless that 4 feet results in someone being in another person's back bumper But again... this is assuming the cars are 110% identical in every way, save for drivetrain... which isn't always the case.
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Forgive me for splitting the hairs. On more than one occasion folks in this thread have maintained AWD was superior in all aspects in winter conditions; all I've been trying to do is to point out the flaw in that logic.
Regarding the extra weight; sorry, a heavier car, all else being equal, will always stop in a longer distance in the snow.
Regarding the extra weight; sorry, a heavier car, all else being equal, will always stop in a longer distance in the snow.
#195
Ex-OEM King
Forgive me for splitting the hairs. On more than one occasion folks in this thread have maintained AWD was superior in all aspects in winter conditions; all I've been trying to do is to point out the flaw in that logic.
Regarding the extra weight; sorry, a heavier car, all else being equal, will always stop in a longer distance in the snow.
Regarding the extra weight; sorry, a heavier car, all else being equal, will always stop in a longer distance in the snow.
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Not sure what you're getting at; you're proposing an apples to grapes comparison; no benefit in that at all.
#197
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Well no, by your logic your lightweight RWD car should stop miles ahead of my heavy AF Jeep. Any car to car differences should be a wash given the vast divide in weight right?
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