Do engines last longer when connected to manual transmissions?

[i]

Fifteen years ago, in a former life, I was buying/selling cars at auctions, and noticed the following odd phenomenon: Cars with manual transmissions invariably had engines that were in better shape. I could never quite come up with a good reason as to why this would be so. It seems to me that an automatic would, over time, be stressing/shocking the engine far less than a manual (considering how badly many people shift). One possible reason I came up with is that maybe people that bought cars with manuals were likely to be "enthusiasts" and were a little more religious about oil changes, but even in cars that were completely dogged inside and out, with every other part destroyed -- the cars with manual trannys had better engines. Has anyone else ever noticed this? Does anyone know why this would be so?

 

[tamu_man]

I'm guessing it's just a state of mind. People that drive a stick generally want more control of the car and are usually more into cars. As such, I would think that they would care more about maintaining the vehicle. Mechanically, the automatics generally have longer gears on the top end and do less revs to compensate for the increased drivetrain loss associated with slush boxes. Automatics also disallow lugging of the engine in most cases. This information would lead you to believe that cars with automatics would last longer. When I see trade-ins at work, I witness your same findings.

 

[toocrazy2yoo]

Can't imagine, but I know that I drive a 5 speed manual simply because except for certain rare high-tech and expensive exceptions, for a given car, manuals offer slightly better gas mileage than the same car with automatic. I can shape my RPM range for a given situation (GWB at rush hour) to scoot through situations getting up the Deegan when traffic is a pretty good imitation of Death Race 2000 (New York City is like that). An automatic would be constantly shifting up and down in that situation, and that wouldn't be good for the engine, but I couldn't say if it's way worse on the engine than a manual. I know I'm as smooth with shifting as an auto would be in this car, without the high-to-low RPM transitions an auto gives you while it "hunts" for the appropriate gear in a changing traffic condition. Couldn't help the engine with all the extra activity an automatic provides Mostly, I get around 170K or more from my clutch, and that's really the only thing that ever goes in normal useage on a manual tranny. That and I replace the gear oil every 30K. $7. Try to replace the auto tranny fluid for that. Clutch in my manual tranny? $600.00 installed with a throwout bearing. Clutches in an automatic? Dunno, never hadda do one, but I bet a year of your salary it's more by at least 2X. But then, I'm a tightwad, and besides, I like the 5 speed, especially with the little sewing machine I drive (1.6 DOHC Accent GT). This thing keeps up, but it doesn't keep UP, ya know? I can't even imagine how snaily it would be with an automatic.

 

[TomJones76]

Maybe guys who have to fight, let's say, Cleveland rush hour traffic choose automatics because they're going to spend a lot of time on the brake, stuck in traffic. Meanwhile, the guys who drive from the country into the edge of one of Cleveland's suburbs (going 64 MPH the whole way on country 2-way blacktop) choose to drive sticks. I know I went from a long, rural commute to a congested urban commute and began looking for a stick shortly thereafter.

 

[moribundman]

I've four owned cars with 5-speed MT and two cars with 3 speed automatics. With the automatics (Buick and Chevy) I always felt I was lugging the poor engine, unless I was cruising or using kickdown. Driving in the mountains. RPM always felt either too low or way too high. My MT cars always had healthy engines for as long as I owned them, with none of them requiring a rebuild or more than new valve stem seals. And I pretty much race my cars, compared to how most other drivers drive their cars. My auto tranny cars had all sorts of engine problems.

 

[Norm Olt]

Unless you live in an area where your driving is far and away primarily comprised of stop-'n-go traffic, a manual should, for the most part, deliver greater average gas mileage IF you are a skilled driver (and most people are, unfortunately, not!). Automatics, on the other hand, are uniformly better in traffic, and can generally (when well-designed) operate at a lower rpm & smack in the middle of the available torque range, which can equal lesser wear on the reciprocating components. I think most people would agree that there is less wear (everything else being equal) running at 2,500 rpm for 100 hours than 4,500 rpm for 100 hours. So, IMHO, in a test situation the automatic should last longer: in REALITY, the skill of the DRIVER makes a bigger difference than auto vs. stick. Your results MAY vary... CHEERS!

 

[icruse]

More important than if the engine is connected to a manual transmission or automatic, is, "Who is connected to the fuel pedal." Good Day, Steven

 

[mechtech]

I think that the manual tranny cars don't run as hot , overall, as their automatic counterparts do. I also agree that manual trans owners are more 'into' their vehicles, and take better care of them.

 

[Mitch Alsup]

I can think of only 1 effect that could be representative of wear on automatics. When idling at a stop light, the auto equipped car has a load on it to turn the fluid clutch and associated transmission stuff, while the manual tranny car dose not. I my auto cars, I shift into neutral at stop lights, the engines sound much less strained and smoother.

 

[den_s]

FYI, all latest automatic tranny vehicles outperform all manuals in Mpg. New automatic design connect drivetrain directly to the engine, just like manuals.

 

[i]

quote:

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Originally posted by JK: another thing......most women drive automatics something to think about

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You may have solved the mystery.

 

[den_s]

In Germany 80% of all cars on the road are manual. In fact if you going to rent one, you must reserve automatic tranny week before due to very limited quantity and more then half of em diesels.

 

[javacontour]

The enthusiast angle combined with the running cooler angle make sense to me. Not all automatic cars get worse highway mileage. When I was looking at the Mazda 3i, the Honda Civic and the Scion tC, all three got better highway mileage with the automatic. I think the stick got better city mileage in most if not all three cases. Of course, they were only a 1 or 2 mpg difference IIRC, but manual trannys today are not the automatic path to improved fuel economy. One other thing to consider, what vehicles are available with a stick? I suspect more Japanese makes are available with stick. (Did I really want to open that can of worms here? LOL)

 

[OriginHacker21]

From my standpoint - I've driven a 1969 Mustang - manual with 3 gears and it was probably the hardest thing I've ever driven. But the fact that it is still running today with original parts says something... (I think it was @ 70k miles). As for older automatics - one can really tell the difference! Technology has sure advanced. I know most of the supercars today have a faster 0-60 with an automatic than a manual (Pontiac GTO, Mercedes Benz sl? 65, etc...). I'll still take a manual anyday over an automatic and I live in Los Angeles. Driving just isn't fun without a manual!!!

 

[Virtuoso]

Manual tranny's can put more stress on an engine's trust bearings through engine braking.

 

[Gary Allan]

Manual tranny's can put more stress on an engine's trust bearings through engine braking. I'd say more from the pushing in of the clutch ..but otherwise I agree. Any old stick engine that's seen any real usage has crank end play. You'll never see it with an automatic. The converter soaks up a lot of shock to the engine. Stuff doesn't as abruptly change speeds. It's still fast ..but if you're counting differences

 

[burnout]

quote:

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Originally posted by toocrazy2yoo: Clutch in my manual tranny? $600.00 installed with a throwout bearing. Clutches in an automatic? Dunno, never hadda do one, but I bet a year of your salary it's more by at least 2X.

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I hope you never DO have to replace a clutch in an automatic

 

[javacontour]

Well, automatic transmissions do have clutch packs and bands, so it's not impossible. How do you think all those gears work? Just because there is no clutch pedal doesn't mean there is no clutch. In fact, doesn't an automatic have MORE clutches than an manual tranny?

 

[brian fix]

I think MechTech is correct on both accounts,,,autos generate more heat which is transfered to engine,when idleing in traffic,there is parts still moving ,and making friction,heat,vs man. ,,as also people whom drive manualsreally do tend to stay on top of maint. issues with their vehicle,,as for man. trans being harder ona engine ,NO,if driven properly,,and yes a manual trans can and does last longer ,using good gear oil,vs a thinner lower viscosity automatic fluid more prone to viscosity breakdown at elevated temps,,,synt. now can be a different story in longtivity of a auto,,,,,,,,,also the type of driving is a big player,highway or stop and go in town?,,,,,,,,which is easyer in both engine and tranny,,yes manual trans do have a positive effect on the engine longtivity vs autos,,,,,,,,,,BL

 

[rainman]

This is purely conjecture, but IF engines hooked to manuals do indeed last longer (note, I say if), could it be that the revs are much more varied? During "normal" driving, an auto car will likely see only between idle and 3000 rpm. Often less. Unless you really stomp on it, the rpm's will never get very high. Most folks who drive a stick (including myself) usually wind the gears out a bit more, even if not accelerating hard. Just something to think about. I tend to agree with the theory that stick drivers are more likely to be enthusiasts, and take care of their cars better. The theory that women less often drive manuals probably has some merit...