How should I drive my 6 speed to get the best gas mileage?
#41
Registered Member
There are numerous variables which affect fuel economy. I you were to try list them all, you might be surprise at how many are on your list and how many you might not have thought of to be part of your list. A fair amount of these variables are things you cannot change. But that leaves a bunch which can be changed.
In September of '05, I got a late start on my vacation trip because the wife and I were watching the development of a hurricane in the Atlantic. So instead of leaving the house at around 4:20 am, we wound up leaving around noon time. The temperature was 86 degrees, my TL was loaded for the trip, and I still had my Bridgestone EL42 OEM tires on the car inflated to 35 front and 32 rear. We gassed up and headed out to moderately heavy traffic. The first 50 miles, we averaged 62 MPH. The next 130 miles, the average was 73 MPH. And the final 80 miles before our fuel stop was between 76 and 78 MPH. The A/C was running the entire time and I was not using any "special" gas saving techniques. My mileage for that first leg of 260 miles was 33.94 MPG calculated.
Our 3G TL's do quite nicely in the economy department when all is considered. As for moving through the air, we have a .29 drag coefficient; a very good number. There is no magic for improving fuel mileage. The same things that worked in the past still work today. The more demand you put on your engine, the less mileage it will return. There is a trade-off and you should try to reach that if you are concerned about such things. Coasting in neutral from speed is never a good idea as someone has already pointed out. You put yourself and others in danger by doing this. Lugging an engine is also not wise because of the increased stress it creates.
So what do you do? Test out different driving scenarios and techniques to find which is the best for you and your needs. Ignore the MID and calculate your mileage when you run your tests and do your fillups at the same pump for your calculations. Run your tests for a week of driving to make sure you cover different conditions. And just drive normally. You may be surprised at your results.
In September of '05, I got a late start on my vacation trip because the wife and I were watching the development of a hurricane in the Atlantic. So instead of leaving the house at around 4:20 am, we wound up leaving around noon time. The temperature was 86 degrees, my TL was loaded for the trip, and I still had my Bridgestone EL42 OEM tires on the car inflated to 35 front and 32 rear. We gassed up and headed out to moderately heavy traffic. The first 50 miles, we averaged 62 MPH. The next 130 miles, the average was 73 MPH. And the final 80 miles before our fuel stop was between 76 and 78 MPH. The A/C was running the entire time and I was not using any "special" gas saving techniques. My mileage for that first leg of 260 miles was 33.94 MPG calculated.
Our 3G TL's do quite nicely in the economy department when all is considered. As for moving through the air, we have a .29 drag coefficient; a very good number. There is no magic for improving fuel mileage. The same things that worked in the past still work today. The more demand you put on your engine, the less mileage it will return. There is a trade-off and you should try to reach that if you are concerned about such things. Coasting in neutral from speed is never a good idea as someone has already pointed out. You put yourself and others in danger by doing this. Lugging an engine is also not wise because of the increased stress it creates.
So what do you do? Test out different driving scenarios and techniques to find which is the best for you and your needs. Ignore the MID and calculate your mileage when you run your tests and do your fillups at the same pump for your calculations. Run your tests for a week of driving to make sure you cover different conditions. And just drive normally. You may be surprised at your results.
#42
I used to calculate my mileage myself for the first year of owning and would always compare it to the MID every time. I found that the MID was never wrong once. The only time there was a discrepancy was when I my mpg calc ended in a .5-9 number. Of course at .5 the MID will simply round off to the next higher number so it was still correct. When you see the MID click over to say 30mpg, it's really at 29.5 and it's rounding off the decimal...
#43
Registered Member
I used to calculate my mileage myself for the first year of owning and would always compare it to the MID every time. I found that the MID was never wrong once. The only time there was a discrepancy was when I my mpg calc ended in a .5-9 number. Of course at .5 the MID will simply round off to the next higher number so it was still correct. When you see the MID click over to say 30mpg, it's really at 29.5 and it's rounding off the decimal...
#44
Three Wheelin'
guys, you're going at this all wrong, the trick to getting great numbers on your mid and your calculated math (miles traveled according to odometer / gallons pumped in car) is to put 12 in wheels on the car
#45
#46
Registered Member
LOL
#48
Moderator
Chapter Leader (South Florida Region)
Chapter Leader (South Florida Region)
iTrader: (6)
I tried using the shift speeds listed above...not as hard as i thought...I will start fresh next tank and see if this yields better mpg...
Truthfully, I haven't even looked at my MID in like 3 months cause I was getting too crazy about staring at it to the point of not enjoying driving the car. I have to say that I have a hard time having some moron cut me off in a PT cruiser and maintaining my cool and 65mph.
When will I grow up?
Truthfully, I haven't even looked at my MID in like 3 months cause I was getting too crazy about staring at it to the point of not enjoying driving the car. I have to say that I have a hard time having some moron cut me off in a PT cruiser and maintaining my cool and 65mph.
When will I grow up?
#49
Three Wheelin'
I tried using the shift speeds listed above...not as hard as i thought...I will start fresh next tank and see if this yields better mpg...
Truthfully, I haven't even looked at my MID in like 3 months cause I was getting too crazy about staring at it to the point of not enjoying driving the car. I have to say that I have a hard time having some moron cut me off in a PT cruiser and maintaining my cool and 65mph.
When will I grow up?
Truthfully, I haven't even looked at my MID in like 3 months cause I was getting too crazy about staring at it to the point of not enjoying driving the car. I have to say that I have a hard time having some moron cut me off in a PT cruiser and maintaining my cool and 65mph.
When will I grow up?
Anyways, my usual 21mpg around town turned out to be 16 mpg today. Mostly because 41mph didn't mean going to 5th gear it meant going to 3rd or 4th.
Also on the way back from the airport my car had one of those uber lazy moments, and it just would not go. I really had to hold gears till 3500 rpm and heavy throttle to keep up with traffic. That happened to me on a few rare occasions in the past. And when that happens I get annoyed with the car making my driving habbits far worse. Needless to say my usual rpm band is 2000 to 3000 rpm, which now was more 3000 to 5000 rpm. I hope my frustration didn't kill too many polar bears.
#50
Moderator
Chapter Leader (South Florida Region)
Chapter Leader (South Florida Region)
iTrader: (6)
mmm...TL-S....nice. Lol...I know what you mean...sometimes I adopt an eff the world attitude and screw this tank of gas and I enjoy it and drive it however...but I usually get remorseful when I plug the mileage into my G1 app and end up at 18 mpg...lol.
#52
Three Wheelin'
oh I forgot, also remeber to always run with you radio off, never use headlights or parking lights. AC off at all times with windows up.
What would you guys on the forum do without my great advice...
btw 26 is not bad, what speed do you travel at on the highway?
I will admit though, my 01. CL-S had better fuel economy that my current TL especially on the highway (about 3-4 mpg better). Smaller engine longer gears and a slicker windshield and rear window helped it stream through the air.
Most impressive is my dads 07 Lexus LS460 which gets 28 mpg on drives from Atlanta (parents house) to Clearwater (my house) and that's with cruise control between 75-80 mph (if traffic conditions permit obviously). And considering that the 1/4 mile time and speed is the same as my TL-S but the car is way bigger, to me that's one heck of an achievement.
What would you guys on the forum do without my great advice...
btw 26 is not bad, what speed do you travel at on the highway?
I will admit though, my 01. CL-S had better fuel economy that my current TL especially on the highway (about 3-4 mpg better). Smaller engine longer gears and a slicker windshield and rear window helped it stream through the air.
Most impressive is my dads 07 Lexus LS460 which gets 28 mpg on drives from Atlanta (parents house) to Clearwater (my house) and that's with cruise control between 75-80 mph (if traffic conditions permit obviously). And considering that the 1/4 mile time and speed is the same as my TL-S but the car is way bigger, to me that's one heck of an achievement.
#57
Well, I drove about an three hours on the highway the other day to go pick something up.. I was going average around 70 - 75 on cruise.. But, after that I only drove to work and back home which is 50/50 hwy/city. On that hwy the speed limit is 65 then 55 at parts.. So average about 60mph on that hwy. I dont drive much over the speed limit on this hwy because of the number of cops patrolling it all the time..
#58
Full of water...
i drove to and from work for around 70 miles, averaging about 55mph overall, but keeping a steady 70mph on the freeway portions(about 90% of the trip) and i was getting around 33-34mpg per the car's computer. i can get around 35 if i am only on the freeway, but once i hit the stop and go side streets it drops...
#59
Three Wheelin'
Well, I drove about an three hours on the highway the other day to go pick something up.. I was going average around 70 - 75 on cruise.. But, after that I only drove to work and back home which is 50/50 hwy/city. On that hwy the speed limit is 65 then 55 at parts.. So average about 60mph on that hwy. I dont drive much over the speed limit on this hwy because of the number of cops patrolling it all the time..
This amount of inaccuracy will definitly change your mpg readings.
#61
Dang I totally forgot about this. If your tires are a larger diameter than stock, your MPH & MPG & odometer readings will all be off.
Lets say your tires are 5% larger than stock. That means your actually getting 5% better MPG than indicated. So your 26MPG is really 27.3mpg.
So here's the questions: What make/model/size tires are you using on the front of the car? Once you know this, you can look up this tires diameter on TireRack.com and compare to the OEM EL42...
Lets say your tires are 5% larger than stock. That means your actually getting 5% better MPG than indicated. So your 26MPG is really 27.3mpg.
So here's the questions: What make/model/size tires are you using on the front of the car? Once you know this, you can look up this tires diameter on TireRack.com and compare to the OEM EL42...
#62
Registered Member
Dang I totally forgot about this. If your tires are a larger diameter than stock, your MPH & MPG & odometer readings will all be off.
Lets say your tires are 5% larger than stock. That means your actually getting 5% better MPG than indicated. So your 26MPG is really 27.3mpg.
So here's the questions: What make/model/size tires are you using on the front of the car? Once you know this, you can look up this tires diameter on TireRack.com and compare to the OEM EL42...
Lets say your tires are 5% larger than stock. That means your actually getting 5% better MPG than indicated. So your 26MPG is really 27.3mpg.
So here's the questions: What make/model/size tires are you using on the front of the car? Once you know this, you can look up this tires diameter on TireRack.com and compare to the OEM EL42...
#63
well. the diameter of the overall wheel doesnt change much.. this is because you change the size of tire. My tire now is WAAAAY thinner then the stock tire. I compared my 19" wheels against my 18" aspecs and they were the same diameter
I also double checked the speed against my old car which was stock.. and the speed was correct.. But the WEIGHT should probably have an effect on my MPG..
I also double checked the speed against my old car which was stock.. and the speed was correct.. But the WEIGHT should probably have an effect on my MPG..
#64
Registered Member
well. the diameter of the overall wheel doesnt change much.. this is because you change the size of tire. My tire now is WAAAAY thinner then the stock tire. I compared my 19" wheels against my 18" aspecs and they were the same diameter
I also double checked the speed against my old car which was stock.. and the speed was correct.. But the WEIGHT should probably have an effect on my MPG..
I also double checked the speed against my old car which was stock.. and the speed was correct.. But the WEIGHT should probably have an effect on my MPG..
#66
Three Wheelin'
Well, it's not exactly like that but close. Going to larger diameter tires has virtually the same effect as does going to a higher final drive, with the exception of the fact that larger diameter tires frequently weigh more. Both the tire rack and the manufacturer's websites are fine places to get this sort of info.
About the wheel size though, just visually, it looks like after market wheel combos fill the wheel wells much better than my factory 17inchers and chunky sidewalls.
And as per the diameter increase mileage decrease formula, what matters is the new tire circumferance.
#67
Your Friendly Canadian
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Diameter of the wheels dont matter as far as MPH indicator differences, only the outer diameter of the tire.
#68
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#70
Registered Member
Two of the significant deciding factors for me when I am researching tires for my car is weight and diameter. Both affect handling and acceleration. Since I rate fuel economy well behind those two factors, I am left with taking a better decision in the end.
#71
Well, it's not exactly like that but close. Going to larger diameter tires has virtually the same effect as does going to a higher final drive, with the exception of the fact that larger diameter tires frequently weigh more. Both the tire rack and the manufacturer's websites are fine places to get this sort of info.
Actually it's EXACTLY like that. Final drive on FWD has NO effect on your speedometer since the VSS samples rpm AFTER the final drive ring gear. On RWD where the speed sensor smples rpm before the final drive, you do have to recalibrate for different gearing...
In FWD, the only determining factor for your speedometer & odometer is TIRE SIZE!!!
So BZYRice, I'll ask again... What make model & size tires do you have?
#72
Three Wheelin'
And for me, as far as picking wheels and tires, I usually go with looks (for wheels) and a good compromise of grip and longevity on tires. It's a street car, with power seats, leather, power everything, so if weight is a 'problem' for me, I really bought the wrong car to start with. Now I do understand that unsprung weight is a bigger performance killer, but I'm really not going to lose sleep over it. I picked this car over a G35 or G37 sedan because it has better fuel economy, so that right there shows my 'concern' for speed.
On the flip side, I won't load up the car with 600lbs worth of sound equipment, and I always keep my car free of un-necessary clutter [some guys i know treat their car like a storage unit].
In the event that one day, I arrive to the grocery store too late, due to the cars lack of performance, I will buy Volk Racing te-37 wheels and Hoosier tires
I am sad to admit that my TL will likely never see a race track, and the sportiest driving it will see is Autocrossing. And for autocrossing, I won't go crazy with toe out in the front, super stiff sway bars, and insane negative rear camber to get the car to pivot.
#74
#75
Team Owner
You can skip gears. Going first to third to 5th works great when you don't have to accelerate hard.
Other than that, everything has been mentioned. In theory, the greatest FE is when the throttle is completely open and the rpms low. Keep that in mind when choosing to downshift or just give it more gas for the same acceeration.
Teach yourself when to coast in gear (no fuel being used) and when to coast in neutral (idle amount of fuel being used). Typically when coasting shorter distances or downhill you want to keep it in gear. If the next redlight is 1/2 mile away, putting it in neutral and coasting farther with your foot off the gas would be best.
#76
Team Owner
Dang I totally forgot about this. If your tires are a larger diameter than stock, your MPH & MPG & odometer readings will all be off.
Lets say your tires are 5% larger than stock. That means your actually getting 5% better MPG than indicated. So your 26MPG is really 27.3mpg.
So here's the questions: What make/model/size tires are you using on the front of the car? Once you know this, you can look up this tires diameter on TireRack.com and compare to the OEM EL42...
Lets say your tires are 5% larger than stock. That means your actually getting 5% better MPG than indicated. So your 26MPG is really 27.3mpg.
So here's the questions: What make/model/size tires are you using on the front of the car? Once you know this, you can look up this tires diameter on TireRack.com and compare to the OEM EL42...
I'm pretty sure but not completely sure that the computer compensates for tire diameter over time using GPS. I noticed mine had a -1.x% compensation in the diagnostics screen which came out to almost exactly the difference in the new tires' diameters over stock.
#77
Three Wheelin'
Pardon my retardedness but what is the theory of best efficiency at full throttle and low rpm? Is it just simply less loss in friction at higher rpm?
For some reason I though internal combustion had a none linear efficiency curve.
That's pretty neat if the car compensates via the gps.
For some reason I though internal combustion had a none linear efficiency curve.
That's pretty neat if the car compensates via the gps.
#78
Teach yourself when to coast in gear (no fuel being used) and when to coast in neutral (idle amount of fuel being used). Typically when coasting shorter distances or downhill you want to keep it in gear. If the next redlight is 1/2 mile away, putting it in neutral and coasting farther with your foot off the gas would be best.
#79
Three Wheelin'
I think this is the major thing I had wrong about trying to save gas while driving stick.. Since before I would put it in neutral right away thinking hat it was saving gas.. so now I am practicing to drive like this now. It isn't an easy transition especially when i am not thinking about it..
I agree it takes some getting use to but don't over do it. I definitly would downshift lower than 4th or maybe 3rd for coasting before stops.
#80
Team Owner
Pardon my retardedness but what is the theory of best efficiency at full throttle and low rpm? Is it just simply less loss in friction at higher rpm?
For some reason I though internal combustion had a none linear efficiency curve.
That's pretty neat if the car compensates via the gps.
For some reason I though internal combustion had a none linear efficiency curve.
That's pretty neat if the car compensates via the gps.