going WOT to save gas?!?!?
#1
Eat my shorts!!
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going WOT to save gas?!?!?
Okay, a friend just told me a technique about going full throttle while shifting early to save gas. For example, I nail the throttle and shift at 3000 rpms as oppose to applying 50% throttle and still shifting at 3000 rpms.
One, wouldn't this damage the engine in the long run?
two, can I do this in an automatic TSX?
and lastly, does this really save fuel?
any car gurus out there want to chime in
One, wouldn't this damage the engine in the long run?
two, can I do this in an automatic TSX?
and lastly, does this really save fuel?
any car gurus out there want to chime in
#2
Drifting
That sounds a bit silly, though I have never tried it.
But if you do that on a carburated car you are dumping gas in, no way it would get you better millage, on modern fuel injected cars they may not just dump the gas in, but i'm shure they would certainly put in more at full throttle.
The best millage I get is just doing the old "pretend there is a egg under the gass pedal" method. Easing on to the gas pedal and never flooring it. I don't think you can do much more than that.
But if you do that on a carburated car you are dumping gas in, no way it would get you better millage, on modern fuel injected cars they may not just dump the gas in, but i'm shure they would certainly put in more at full throttle.
The best millage I get is just doing the old "pretend there is a egg under the gass pedal" method. Easing on to the gas pedal and never flooring it. I don't think you can do much more than that.
#3
How can that be possible if gas is combusted at a higher rate at wide open throttle.
Lower the rpm's the less gas you are burning.
Nothing more annoying then someone who pulses the gas pedal every 30 seconds. Gives me a headache.Maybe you are one of them. I could not for the life of me explain this phenomena to my mother who drives like total crap so I just told her to WOT the damn car. lol
Lower the rpm's the less gas you are burning.
Nothing more annoying then someone who pulses the gas pedal every 30 seconds. Gives me a headache.Maybe you are one of them. I could not for the life of me explain this phenomena to my mother who drives like total crap so I just told her to WOT the damn car. lol
#5
Originally Posted by speedzer
Okay, a friend just told me a technique about going full throttle while shifting early to save gas. For example, I nail the throttle and shift at 3000 rpms as oppose to applying 50% throttle and still shifting at 3000 rpms.
One, wouldn't this damage the engine in the long run?
two, can I do this in an automatic TSX?
and lastly, does this really save fuel?
any car gurus out there want to chime in
One, wouldn't this damage the engine in the long run?
two, can I do this in an automatic TSX?
and lastly, does this really save fuel?
any car gurus out there want to chime in
Efficiency favors relatively high loads because gas burns most efficiently at relatively high pressure. On a throttled gasoline engine, this does mean fairly heavy throttle since otherwise there is only very low pressure in the engine. One of the big reasons that diesels are so much more efficient is because they're unthrottled and always operate with high excess air ratios (high cylinder pressure) whether it's idling or at WOT.
Efficiency also favors lower RPM, and this one is easy. Friction in the engine rises exponentially with increasing RPM, so the lower you can keep the revs the more efficiently the engine will operate.
The net result is that if you do use heavier throttle while also keeping the engine at lower RPMs, you should be able to improve your mileage a tad depending on your specific drive cycle (YMMV). In fact one of the reasons that gasoline ICE's are so inefficient in automobiles is because of the fact that most of the time they're just cruising along and very lightly loaded. Efficiency is horrible in that state of operation with gas engines, but not with diesels which continue to have very good efficiency over a much wider range of RPMs and loads.
The kicker though is that your TSX has electronic throttle control. It's actually already doing a lot of this for you and the added efficiency from techniques like this is built into the car. Everybody loves their extra power nowadays, but one of the big reasons that efficiency has also been maintained or improved is because of electronic throttling. Works wonders for optimizing shift schedules and improving fuel efficiency while not pissing off owners who would feel like their car was lagging big time and complain if you did the same thing with a conventional throttle.
#6
One on the right for me
Originally Posted by Maximized
He must of read MT or R&T. They had an article on this.
I remember reading something about it also in one of those magazines. At the time I was only driving my mustang and that fucking thing never gets good mileage so I give the article the time of day.
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#8
Originally Posted by SteVTEC
The following is the Brake Specific Fuel Consumption map for a Toyota 1MZ-FE 3.0L DOHC V6, in grams of fuel used per kilowatt-hour of energy produced (g/kW-hr). Lower number is better. Most internal combustion engines have BSFC maps that look about like this.
Efficiency favors relatively high loads because gas burns most efficiently at relatively high pressure. On a throttled gasoline engine, this does mean fairly heavy throttle since otherwise there is only very low pressure in the engine. One of the big reasons that diesels are so much more efficient is because they're unthrottled and always operate with high excess air ratios (high cylinder pressure) whether it's idling or at WOT.
Efficiency also favors lower RPM, and this one is easy. Friction in the engine rises exponentially with increasing RPM, so the lower you can keep the revs the more efficiently the engine will operate.
The net result is that if you do use heavier throttle while also keeping the engine at lower RPMs, you should be able to improve your mileage a tad depending on your specific drive cycle (YMMV). In fact one of the reasons that gasoline ICE's are so inefficient in automobiles is because of the fact that most of the time they're just cruising along and very lightly loaded. Efficiency is horrible in that state of operation with gas engines, but not with diesels which continue to have very good efficiency over a much wider range of RPMs and loads.
The kicker though is that your TSX has electronic throttle control. It's actually already doing a lot of this for you and the added efficiency from techniques like this is built into the car. Everybody loves their extra power nowadays, but one of the big reasons that efficiency has also been maintained or improved is because of electronic throttling. Works wonders for optimizing shift schedules and improving fuel efficiency while not pissing off owners who would feel like their car was lagging big time and complain if you did the same thing with a conventional throttle.
Efficiency favors relatively high loads because gas burns most efficiently at relatively high pressure. On a throttled gasoline engine, this does mean fairly heavy throttle since otherwise there is only very low pressure in the engine. One of the big reasons that diesels are so much more efficient is because they're unthrottled and always operate with high excess air ratios (high cylinder pressure) whether it's idling or at WOT.
Efficiency also favors lower RPM, and this one is easy. Friction in the engine rises exponentially with increasing RPM, so the lower you can keep the revs the more efficiently the engine will operate.
The net result is that if you do use heavier throttle while also keeping the engine at lower RPMs, you should be able to improve your mileage a tad depending on your specific drive cycle (YMMV). In fact one of the reasons that gasoline ICE's are so inefficient in automobiles is because of the fact that most of the time they're just cruising along and very lightly loaded. Efficiency is horrible in that state of operation with gas engines, but not with diesels which continue to have very good efficiency over a much wider range of RPMs and loads.
The kicker though is that your TSX has electronic throttle control. It's actually already doing a lot of this for you and the added efficiency from techniques like this is built into the car. Everybody loves their extra power nowadays, but one of the big reasons that efficiency has also been maintained or improved is because of electronic throttling. Works wonders for optimizing shift schedules and improving fuel efficiency while not pissing off owners who would feel like their car was lagging big time and complain if you did the same thing with a conventional throttle.
#9
Originally Posted by Edr0e
How can that be possible if gas is combusted at a higher rate at wide open throttle.
100 N-m x 4000 rpm = 56 hp and 300 g/kW-hr
200 N-m x 2000 rpm = 56 hp and 240 g/kW-hr
It's far more efficient to produce 56 hp at near-WOT and 2000 rpm than it is to produce the same 56 hp at 4000 rpm and only about 1/3rd throttle. The reason being is that friction is a lot lower at 2000 rpm so you have much less energy loss due to friction. The other reason is the higher pressure that the fuel is combusting under, which again allows for much more efficient combustion than at lower pressure.
This theory of operation is why GM can get 29 mpg out of their LS1 V8 engines. They run just above idle on the highway and as a result have very low friction. And at 60-70 mph they only have about 70 hp available. So average load on the engine ends up being a lot heavier which is more efficient and that's where the 29 mpg comes from. The same theory is behind the 1-4 skip-shift feature which was common on a lot of their cars. If you're not accelerating hard, 2 and 3 are blocked and 4th is what you get. Lower RPM and higher load = better efficiency, and GM delivers you a powerful vehicle that gets decent fuel mileage. Ditto on variable displacement engines. Different way to accomplish the same thing.
#11
Originally Posted by SteVTEC
From the BSFC map, 100 N-m of torque at 4000 rpm and 200 N-m of torque at 2000 rpm will both produce the same exact amount of power, about 56 hp after converting.
100 N-m x 4000 rpm = 56 hp and 300 g/kW-hr
200 N-m x 2000 rpm = 56 hp and 240 g/kW-hr
It's far more efficient to produce 56 hp at near-WOT and 2000 rpm than it is to produce the same 56 hp at 4000 rpm and only about 1/3rd throttle. The reason being is that friction is a lot lower at 2000 rpm so you have much less energy loss due to friction. The other reason is the higher pressure that the fuel is combusting under, which again allows for much more efficient combustion than at lower pressure.
This theory of operation is why GM can get 29 mpg out of their LS1 V8 engines. They run just above idle on the highway and as a result have very low friction. And at 60-70 mph they only have about 70 hp available. So average load on the engine ends up being a lot heavier which is more efficient and that's where the 29 mpg comes from. The same theory is behind the 1-4 skip-shift feature which was common on a lot of their cars. If you're not accelerating hard, 2 and 3 are blocked and 4th is what you get. Lower RPM and higher load = better efficiency, and GM delivers you a powerful vehicle that gets decent fuel mileage. Ditto on variable displacement engines. Different way to accomplish the same thing.
100 N-m x 4000 rpm = 56 hp and 300 g/kW-hr
200 N-m x 2000 rpm = 56 hp and 240 g/kW-hr
It's far more efficient to produce 56 hp at near-WOT and 2000 rpm than it is to produce the same 56 hp at 4000 rpm and only about 1/3rd throttle. The reason being is that friction is a lot lower at 2000 rpm so you have much less energy loss due to friction. The other reason is the higher pressure that the fuel is combusting under, which again allows for much more efficient combustion than at lower pressure.
This theory of operation is why GM can get 29 mpg out of their LS1 V8 engines. They run just above idle on the highway and as a result have very low friction. And at 60-70 mph they only have about 70 hp available. So average load on the engine ends up being a lot heavier which is more efficient and that's where the 29 mpg comes from. The same theory is behind the 1-4 skip-shift feature which was common on a lot of their cars. If you're not accelerating hard, 2 and 3 are blocked and 4th is what you get. Lower RPM and higher load = better efficiency, and GM delivers you a powerful vehicle that gets decent fuel mileage. Ditto on variable displacement engines. Different way to accomplish the same thing.
So this applies to engines with throttles only?
#12
Originally Posted by Edr0e
2200 rpms is when you should shift eh?
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