# Better gas mileage in a manual transmission? **URL:** \ **Category:** Factual Questions\ **Created:** [December 7, 2005, 5:36am UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476 "2005-12-07T05:36:54Z")\ **Posts on this page:** 13\ **Page:** 2
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [December 8, 2005, 8:34pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/21 "2005-12-08T20:34:59Z")
> [@chaparralv8](#): > > Goes to show that the Volvo manual gearbox isn’t any good… check the difference between the manual and automatic versions of the Civic. **WTF?** How do you get that from the EPA numbers? Got a cite for that? Furthermore I did check the Honda web [site](http://automobiles.honda.com/models/specifications_full_specs.asp?ModelName=Civic+Sedan&Category=3) the EPA numbers for a Civic are: Manual 30/38 Auto 30/40 so contary to what you posted > [@](#): > > I’ve never seen an automatic car get close to the EPA numbers in the city many cars get exactly the same mileage in the city, and almost the same or better on the highway. > [@](#): > > Also remember that the automatic is programmed for optimal EPA mileage at the expense of everything else. Although the plural of anecdote is not data, I have a sufficiently large sample size to make the categorical statement that there is no automatic car that meets its EPA ratings in actual service. Again I have a feeling you have no clue as to what you are talking about. If we built a transmission that > [@](#): > > shifting very early and very hard (to use the rotational momentum of the engine to turn the wheels) and the torque converter locking up in the lower gears. we would be up to our ass in customer complaints, and would be buying cars back right and left. I can guarentee that we do not do this at Volvo. I cannot speak for any other car makers, but I can tell you that we don’t do this. If you insist that I am wrong, when come back bring cite. ---
**Author:** ![The\_Weird\_One](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@The\_Weird\_One](https://boards.straightdope.com/u/The_Weird_One)\ **Post date:** [December 8, 2005, 8:59pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/22 "2005-12-08T20:59:57Z")
Nobody knows nothing about Continuously Variable Transmission? Shoot. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [December 9, 2005, 2:02am UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/23 "2005-12-09T02:02:40Z")
> [@The Weird One](#): > > Nobody knows nothing about Continuously Variable Transmission? Shoot. Well, a quick search for the Ford Five Hundred MY 2006 indicates this: V6 with six-speed auto: 21 / 29 EPA est. V6 with CVT: 20 / 27 EPA est. Now I’m kind of wondering what the purpose of the CVT is – the Five Hundred’s automatic transmission shifting is completely smooth and unnoticable, and you don’t need a CVT to make it comfortable. I’d never looked up those number before – that’s some damn good economy for a true, full-size car! ---
**Author:** ![JimOfAllTrades](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@JimOfAllTrades](https://boards.straightdope.com/u/JimOfAllTrades)\ **Post date:** [December 9, 2005, 3:21am UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/24 "2005-12-09T03:21:36Z")
> [@chaparralv8](#): > > Although the plural of anecdote is not data, I have a sufficiently large sample size to make the categorical statement that there is no automatic car that meets its EPA ratings in actual service. And as usual for categorical statements, you’re wrong. According to this page: [http://www.fueleconomy.gov/feg/noframes/12896.shtml](http://www.fueleconomy.gov/feg/noframes/12896.shtml) the EPA rating for my 1996 Pontiac Bonneville (6 cylinder, 3.8 liter, 4 speed auto, air, power everything) is 17 mpg city and 26 highway. According to this site: > **[Expert Car Reviews | Consumer Guide Auto | consumerguide.com](https://consumerguide.com)** > > At Consumer Guide Automotive, we strive to make the complicated car-buying experience less daunting, all while helping you pick out the vehicle that’s best for you. As such, we hope you find this website to be the fastest and easiest way to begin the... the EPA rating is 19 city and 29 highway. Not sure why the difference, but it’s not huge. But I actually get about 21 city and 29 highway. I used to get over 30 on the highway, and have done as well as 32 on trips, but the car is 10 years old now, and it’s dropped off a touch. And I’m not a soft driver. ---
**Author:** ![chaparralv8](https://avatars.discourse-cdn.com/v4/letter/c/e274bd/32.png) [@chaparralv8](https://boards.straightdope.com/u/chaparralv8)\ **Post date:** [December 9, 2005, 4:44am UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/25 "2005-12-09T04:44:06Z")
> [@Rick](#): > > Again I have a feeling you have no clue as to what you are talking about. If we built a transmission that we would be up to our ass in customer complaints, and would be buying cars back right and left. I can guarentee that we do not do this at Volvo. I cannot speak for any other car makers, but I can tell you that we don’t do this. If you insist that I am wrong, when come back bring cite. I can’t find it now. It is an old (1991?) SAE paper by a GM engineer about the Saturn’s transmission recognizing the EPA city cycle and shifting accordingly. It specifically mentioned increased shift speed at lower speeds during the EPA cycle. It was cited in the August 2001 (037) issue of EVO magazine during a test of various gearboxes ranging from full manuals to full automatics. I can get it in a couple weeks if it’s still of interest. Speaking as an outsider on these matters, I wonder why you wouldn’t do that if you don’t now. It would only take a section of code activated by a surreptitiously flipped switch and it would be damned near undetectable. It would get ugly\* if you got caught but if I can hide traction control on a (carbureted, no ABS, no sensors on throttle) car successfully with race inspectors knowing the car had it and looking specifically for it, you can hit one dip-switch without the EPA noticing. Do you have an explanation for why automatic transmissions have developed faster than manuals over the past ten or so years? At least on paper it shouldn’t even be close - one set of meshing gears and a locked clutch versus two or three planetary gearsets and a torque converter that still wastes enough energy to need a separate heat exchanger in some cases. \*REALLY ugly, fast! ---
**Author:** ![chaparralv8](https://avatars.discourse-cdn.com/v4/letter/c/e274bd/32.png) [@chaparralv8](https://boards.straightdope.com/u/chaparralv8)\ **Post date:** [December 9, 2005, 4:45am UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/26 "2005-12-09T04:45:40Z")
As for the Civic, that used to be a great example… four or five years ago. I guess Honda got on the ball with AT design since I last researched it. You guys are sharp. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 9, 2005, 2:12pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/27 "2005-12-09T14:12:55Z")
> [@](#): > > Do you have an explanation for why automatic transmissions have developed faster than manuals over the past ten or so years? I think that a m/t is pretty close to full efficency as it is, it is a simple design and there is just not much room to make it ‘better’. Also it is limited by that unit between the steering wheel and gas pedel, and his ability to opperate the m/t while opperating the rest of the car (and eating his Big Mac EVM while talking to his g/f on his cellphone and reading the map). A A/T has a lot of room for improvement, the heat generation as noted above it one area where it can be made more efficient, also the size of the unit is another, as we are able to make these things smaller we can add more gears, which improve effiniency. Back in the day you had a choice of a 4 or 5 speed manual or a 3 speed a/t. Now it is common to have a 4 or 5 speed a/t and a locking torque converter which effectivally adds another gear. It appears that a/t are now much stronger also, again back in the day a a/t would go nowhere near redline with the possiable exception of WOT - but not even all the time then, now it commonly will go right to redline before shifting, many times with the gas pressed a bit more then 1/2 way. Also I don’t know if this is across all lines, but it appears that some AWD cars/suv’s (subies and volvos IIRC but perhaps more) use a different technology for m/t vs. a/t, with the a/t version usually superior in that is it ‘active’ AWD while the m/t version is reactive and slippage must occur before power is shifted. I suspect that the a/t worked in conjunction with the drive system in a way that a m/t just can’t. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [December 9, 2005, 2:15pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/28 "2005-12-09T14:15:56Z")
> [@chaparralv8](#): > > Do you have an explanation for why automatic transmissions have developed faster than manuals over the past ten or so years? At least on paper it shouldn’t even be close - one set of meshing gears and a locked clutch versus two or three planetary gearsets and a torque converter that still wastes enough energy to need a separate heat exchanger in some cases. > > \*REALLY ugly, fast! In the manual transmission I’ve worked on all of the gears are engaged all of the time except for the reverse idler. They are only connected to the output shaft one set at a time. ---
**Author:** ![chaparralv8](https://avatars.discourse-cdn.com/v4/letter/c/e274bd/32.png) [@chaparralv8](https://boards.straightdope.com/u/chaparralv8)\ **Post date:** [December 9, 2005, 2:20pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/29 "2005-12-09T14:20:12Z")
All the gears are turning but only one set is under load. Unloaded gear friction is very small compared to loaded gear friction. I wonder if anyone in the production department has thought about taking advantage of the viscous losses: i.e. using them as a set of gear pumps. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [December 9, 2005, 5:04pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/30 "2005-12-09T17:04:39Z")
Why has auto trans technology moved ahead so fast and so far? could it be that about 98% of our production for the US is in automatics? Also, where is there room for improvement with a manual? Clutchs and flywheels have gotten better ove rthe last 10-15 years with self adjusting clutches (pressure plate adjusts for disc wear) and dual mass flywheels that make starting off from a stop easier for the novice stick driver (but somewhat harder for a seasoned stick driver to drive really smoothly) Other than that, where are you going to go with M/T technology? As far as hiding a dip switch, I can’t speak for other companies, but we don’t cheat. If the rules say that we do the EPA test cycle this way, then we do it that way. Careful with that broad brush, not all companies are the same. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 9, 2005, 7:07pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/31 "2005-12-09T19:07:03Z")
> [@](#): > > Other than that, where are you going to go with M/T technology? Another factor is how much more can we expect a driver to do. We already require a hand and a foot for shifting, the other hand for steering, the other foot for gas/brake. If we have some other thing for him to do, perhaps he can hit a swtich with his left ear. Or perhaps the stick can have controls mounted on them like how we think of a fighter plane stick. ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [December 9, 2005, 7:12pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/32 "2005-12-09T19:12:36Z")
> [@kanicbird](#): > > Another factor is how much more can we expect a driver to do. We already require a hand and a foot for shifting, the other hand for steering, the other foot for gas/brake. If we have some other thing for him to do, perhaps he can hit a swtich with his left ear. > > Or perhaps the stick can have controls mounted on them like how we think of a fighter plane stick. I just saw an ad (in a year old magazine) for a Cadillac with a 6 speed manual transmission. My how the typical driver could screw _that_ up. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [December 9, 2005, 7:41pm UTC](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476/33 "2005-12-09T19:41:46Z")
You are correct in that. I have driven 6 speeds in Volvos and have found (more than once) that I have been in 3rd gear at 70 mph, instead of 6th. :smack: Damn car is too quiet, I could never make that mistake in my old MG (3rd for 4th it didn’t have 6 to choose from) [Previous page](https://boards.straightdope.com/t/better-gas-mileage-in-a-manual-transmission/334476.md?page=1)