2009 Fit Fuel Efficiency: MT vs AT
#21
Hello all,
This is my first post in the forum, I just recently registered though I've been lurking since last spring. I've been wanting a Fit forever and it's finally going to happen, I'm planning on getting an 09 Sport with a manual transmission. The idea of getting the manual was to achieve maximum fuel efficiency, but now I am reading that the automatic gets slightly better than the manual. I've heard some talk of gear ratios but I don't really understand what it all means. I'm not a 'showy' driver; I build up speed slowly, go 60-65 on the highway, basically 'drive like grandma'. Is it still possible to get the best fuel efficiency with a manual transmission with careful, efficient handling of the car? Or will the automatic really do better?
Thanks!
This is my first post in the forum, I just recently registered though I've been lurking since last spring. I've been wanting a Fit forever and it's finally going to happen, I'm planning on getting an 09 Sport with a manual transmission. The idea of getting the manual was to achieve maximum fuel efficiency, but now I am reading that the automatic gets slightly better than the manual. I've heard some talk of gear ratios but I don't really understand what it all means. I'm not a 'showy' driver; I build up speed slowly, go 60-65 on the highway, basically 'drive like grandma'. Is it still possible to get the best fuel efficiency with a manual transmission with careful, efficient handling of the car? Or will the automatic really do better?
Thanks!
The EPA fuel economy tsts are very carefully controlled by computer to a very specific set of speeds, routes, and engine loads that manufacturers really carefully tune their test engines to be very efficient. The tests, both city and highway are nothing like we drive. They are intended to give a valid comparison between cars so the public will have a good idea what kind of gas mileage they can expect. Having said that we don't drive that way; most of us don't get the mpg of those tests.\, mainly because they are a lot like grandma driving.
For most equally skilled drivers, manual transmissions offer the best chanes for getting the best mileage unless the manufacturer tunes the manual for the highest performance. Automatics, especially ones with CVT transmissions, will get close to manuals but rarely exceed them u nder equal conditions. If the highest gear ratio of an automatic causes its engine to turn fewer revolutions per mile traveled than does a manual on the same engine, then it is possible, even probable, that the auto will get better mpg. That isn't a given because the friction losses in an automatic are greater than for a manual.
As you can see by searching this site far more manual Fit owners report getting 40 mpg than those with automatic Fits.
So if you are looking for maximum efficiency expect the manual to be better for mpg. Just like you thought. Drive carefully and safely.
cheers.
#22
The EPA fuel economy tsts are very carefully controlled by computer to a very specific set of speeds, routes, and engine loads that manufacturers really carefully tune their test engines to be very efficient. The tests, both city and highway are nothing like we drive. They are intended to give a valid comparison between cars so the public will have a good idea what kind of gas mileage they can expect. Having said that we don't drive that way; most of us don't get the mpg of those tests.\, mainly because they are a lot like grandma driving.
For most equally skilled drivers, manual transmissions offer the best chanes for getting the best mileage unless the manufacturer tunes the manual for the highest performance. Automatics, especially ones with CVT transmissions, will get close to manuals but rarely exceed them u nder equal conditions. If the highest gear ratio of an automatic causes its engine to turn fewer revolutions per mile traveled than does a manual on the same engine, then it is possible, even probable, that the auto will get better mpg. That isn't a given because the friction losses in an automatic are greater than for a manual.
As you can see by searching this site far more manual Fit owners report getting 40 mpg than those with automatic Fits.
So if you are looking for maximum efficiency expect the manual to be better for mpg. Just like you thought. Drive carefully and safely.
cheers.
For most equally skilled drivers, manual transmissions offer the best chanes for getting the best mileage unless the manufacturer tunes the manual for the highest performance. Automatics, especially ones with CVT transmissions, will get close to manuals but rarely exceed them u nder equal conditions. If the highest gear ratio of an automatic causes its engine to turn fewer revolutions per mile traveled than does a manual on the same engine, then it is possible, even probable, that the auto will get better mpg. That isn't a given because the friction losses in an automatic are greater than for a manual.
As you can see by searching this site far more manual Fit owners report getting 40 mpg than those with automatic Fits.
So if you are looking for maximum efficiency expect the manual to be better for mpg. Just like you thought. Drive carefully and safely.
cheers.
Mark
#23
I think for the most part the MT gets slightly better overall mileage. I haven't driven a Fit with the automatic, but based on past vehicles I've driven with a small four cylinder engine mated to a slushbox I'd definitely get the manual.
The world needs more manual drivers anyway.
2003 VW Jetta with 2.0L and 5 speed = lots of fun, very responsive.
2004 VW New Beetle, 2.0L, auto = This car drove weird. It felt mushy and unresponsive.
2003 Nissan Sentra, 1.8L, auto: Same unresponsiveness on acceleration.
Although apparently the Fit's autobox locks up the torque converter in all gears, so that should help some.
The world needs more manual drivers anyway.
2003 VW Jetta with 2.0L and 5 speed = lots of fun, very responsive.
2004 VW New Beetle, 2.0L, auto = This car drove weird. It felt mushy and unresponsive.
2003 Nissan Sentra, 1.8L, auto: Same unresponsiveness on acceleration.
Although apparently the Fit's autobox locks up the torque converter in all gears, so that should help some.
#24
The Fit's 1.5L is exceptionally under-square (long piston stroke), and the lower rpms are preferred for best efficiency. This is totally dominated by m/t -- people with the a/t lose on both counts -- natural slushbox losses, and going to higher rpms to regain that power throws them out of the engine's better efficiency range.
a/t can get great mpg, you're just going slow. Not having CVT here should be a punishable crime...
That big chart -- the a/t is not 2200 rpms @ 65 mph, more like 2400.
a/t can get great mpg, you're just going slow. Not having CVT here should be a punishable crime...
That big chart -- the a/t is not 2200 rpms @ 65 mph, more like 2400.
Last edited by xorbe; 08-30-2008 at 10:42 AM.
#26
Fair MPG
Hi All,
My 07 Fit Sport AT avgs around 33MPG on a commute to, from, in and around Boston 5 days a week. I drive around 68-70 MPH on highway and sit in stop and go traffic part of the day.
After 97,000 miles, I still love my Fit.
Original Brakes
New Catalytic Converter at 79K. (if you need one, get it before 80K or it is not covered under warranty, not even Honda Care).
2nd set of tires.
New Wiper linkage tomorrow. (Honda Care)
Other than that, she's still rolling strong.
Good Luck to all.
My 07 Fit Sport AT avgs around 33MPG on a commute to, from, in and around Boston 5 days a week. I drive around 68-70 MPH on highway and sit in stop and go traffic part of the day.
After 97,000 miles, I still love my Fit.
Original Brakes
New Catalytic Converter at 79K. (if you need one, get it before 80K or it is not covered under warranty, not even Honda Care).
2nd set of tires.
New Wiper linkage tomorrow. (Honda Care)
Other than that, she's still rolling strong.
Good Luck to all.
#28
Auto engineer's POV
While gearing is an important factor in fuel efficiency with lower rev's being better, all other things equal, there is another reason why manual's have a distinct advantage over Automatics. Every automatic is power hydraulically by an internal oil pump. This pump is running constantly and is an additional parasitic loss that the manual transmission doesn't have.
So the tall gearing on the Auto makes up for the additional drag of the automatic's hydraulic system. There are other sources of increased drag in an Auto-box. On the basis of simple transmission efficiency, you can't beat a manual gearbox. Also, the auto-trans weighs significantly more than the manual, which hurts city fuel mileage and (at least theoretically) the handling and braking ability of the car.
The main reason that the EPA numbers on maual transmissions are much lower than what a skilled driver can get is that the EPA test is shifted without regard to performance or efficiency (or feel) but shifts are jsut done at specific vehicle speeds. You could say that the EPA shift schedule represents a very unskilled driver!
By my thinking and training, the way to drive a maual transission for performance and economy is to use the following algorithm:
For the next 10 seconds of driving, if I shift up to the next higher gear, will I be able to acclerate as much as I want to without lugging the engine? If yes, then shift up, if not hold your gear or shift down. You should always be thinking if you can go up a gear (without causing lugging).
The basic principle behind keeping the rev's down is to minimize engine friction which is a function of engine speed, and to open the throttle as much as possible to lower throttling losses. If the second part doesn't make sense, see "http://carambola.usc.edu/Research/TPCE/TPCE.html
Any internal combustion engine is most efficient at or near full throttle (if it is not running rich).
The Fit mainal would certainly get better highway fe with a taller top gear.
So the tall gearing on the Auto makes up for the additional drag of the automatic's hydraulic system. There are other sources of increased drag in an Auto-box. On the basis of simple transmission efficiency, you can't beat a manual gearbox. Also, the auto-trans weighs significantly more than the manual, which hurts city fuel mileage and (at least theoretically) the handling and braking ability of the car.
The main reason that the EPA numbers on maual transmissions are much lower than what a skilled driver can get is that the EPA test is shifted without regard to performance or efficiency (or feel) but shifts are jsut done at specific vehicle speeds. You could say that the EPA shift schedule represents a very unskilled driver!
By my thinking and training, the way to drive a maual transission for performance and economy is to use the following algorithm:
For the next 10 seconds of driving, if I shift up to the next higher gear, will I be able to acclerate as much as I want to without lugging the engine? If yes, then shift up, if not hold your gear or shift down. You should always be thinking if you can go up a gear (without causing lugging).
The basic principle behind keeping the rev's down is to minimize engine friction which is a function of engine speed, and to open the throttle as much as possible to lower throttling losses. If the second part doesn't make sense, see "http://carambola.usc.edu/Research/TPCE/TPCE.html
Any internal combustion engine is most efficient at or near full throttle (if it is not running rich).
The Fit mainal would certainly get better highway fe with a taller top gear.
#29
so basically what your saying is the automatic is better
of corse it is on the highway.
just look at the chart and tell me an auto will
not get better mpg on highway than a mt.
i think the auto wins on highway.
and mt wins in the city.
of corse it is on the highway.
just look at the chart and tell me an auto will
not get better mpg on highway than a mt.
i think the auto wins on highway.
and mt wins in the city.
#31
About 2/3 of my commute is on the highway, but I do a bit of driving around town too. Not really city driving, kind of rural town driving. I don't think it's the 1-2 MPG difference that really bothers me so much as the initial decision to go manual was because I thought there would be a significant advantage in fuel economy. Now that that's not so much the case, maybe I might as well go with the automatic because it's easier? I enjoy driving stick but it can be frustrating at times too. I don't know what to do!
#32
In the end it comes down to what you'll enjoy the most. I wouldn't worry about a 1-2 mpg difference, as it's really not that much difference in the big picture. Going out to dinner costs a lot these days, but nobody gives much thought to spending on a small fortune on dinner and drinks, which will be history in 24 hours
#33
I am not saying that the Auto is better. One of my main points is that Auto-tranny's are less efficient and they are heavier. That is why, if the gear ratios are similar, the Manual, properly driven, will get a lot better gas mileage than an Auto-trans. In the Fit, the higher rpm's waste some gas, but the Auto trnasmission is turning more of the poweri input into waste heat.
My overall estimate is that the highway fe will be roughly the same between the 2 gearboxes, just as the EPA predicts.
Dave
My overall estimate is that the highway fe will be roughly the same between the 2 gearboxes, just as the EPA predicts.
Dave
#34
I drive to work once every four days. Richmond, VA to Washingotn D.C.
118 miles one way.
Approx. 110 miles of that is interstate travel.
75% of that, I'll be running 70-80mph.
IF that chart is correct, I'll be running almost 800 more rpm on over 90% of my trip with a MT than I would with an AT.
I imagine that 800 rpm over 110 miles would impact my fuel mileage significantly. I've always been a guy who would only drive a manual transmission, but that philosophy may change here shortly. I'll be test driving both a MT and an AT later this week. I'll be paying attention to the rpm as I drive. As long as the AT doesn't 'gear hunt' too much (like my girlfriend's Toyotta Corolla), I think I'll be buying an auto.
118 miles one way.
Approx. 110 miles of that is interstate travel.
75% of that, I'll be running 70-80mph.
IF that chart is correct, I'll be running almost 800 more rpm on over 90% of my trip with a MT than I would with an AT.
I imagine that 800 rpm over 110 miles would impact my fuel mileage significantly. I've always been a guy who would only drive a manual transmission, but that philosophy may change here shortly. I'll be test driving both a MT and an AT later this week. I'll be paying attention to the rpm as I drive. As long as the AT doesn't 'gear hunt' too much (like my girlfriend's Toyotta Corolla), I think I'll be buying an auto.
#37
Being that much of my driving is at a constant RPM on the highway, the previous statement should hold true for me.
I am looking for a car that maximizes my highway fuel mileage, without paying the premium for a hybrid or diesel engine.
#38
Not necessarily. You will be using less fuel per combustion at the same vehicle velocity. You have to look at the efficiency curve of the engine. Of course more rpms means more friction losses, but it's not a linear relationship with rpms.
Last edited by xorbe; 09-08-2008 at 07:16 PM.
#39
So I ended up going with the AT, it's sitting in my driveway right now! I just took it home today and am very satisfied with my choice. I was so on the fence about the MT/AT thing, I decided to just go with the AT because at least it's a bit of a compromise with the paddle shifters. I probably would have been just as happy with an MT...but oh well! Descision is made and I'm glad it's all over and done with and I have my lovely new car. I've only just drove it from the dealership to home, I was so beat after a loooong day of driving all over Massachusetts to get my financing and insurance in order, go to the dealership, go to work, go back to the dealer to pick it up...I'm done!
Not sure how accurate the MPG gauge on the dash is, but I averaged about 40mpg just on the drive home (back rural roads). The highway should be fun tomorrow, I'll let you all know how it goes.
Not sure how accurate the MPG gauge on the dash is, but I averaged about 40mpg just on the drive home (back rural roads). The highway should be fun tomorrow, I'll let you all know how it goes.
#40
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What color did you get? Congratulations and please post pics!!
I got an AT b/c it seemed to me that with the paddle shifter option, I got the best of both configs...some people might disagree but it helped me make up my mind. I can't have an automatic if I got a straight manual, but I could have a sort-of manual if I got the AT Sport. Does that make sense?
I got an AT b/c it seemed to me that with the paddle shifter option, I got the best of both configs...some people might disagree but it helped me make up my mind. I can't have an automatic if I got a straight manual, but I could have a sort-of manual if I got the AT Sport. Does that make sense?