Quote:
Originally Posted by rackley
That's because you have an AT car. Most or all of the evidence points to the 7AT cars not having the overheating problem nearly as bad as the MT cars. My buddy here on base has a 7AT and he cruises at 200*F and rarely hits 220 even with hard driving. My bottom oil temp is 220 and I go up from there to 250 before I pull over for fear of melting the engine.
7ATs do not seem to have the overheating problem nearly as bad. So because you have a 7AT without an overheating problem does not invalidate the experiences of everyone else with MTs who are overheating.
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If there's any difference between 6MT and 7AT in this regard, it pretty much has to come down to one of a few things:
1) If the 7AT's fluid is cooled by the radiator (there are hard lines plumbed straight into the radiator from the transmission, IIRC, but I'll have to go look again or check the svc manual), this may have some sort of indirect effect on the overall cooling efficiency of the car, in some way that I can't imagine right now.
Edit: confirmed this in the svc manual, TM.pdf Pg 295, we do have transmission fluid lines running to the radiator on the 7AT
2) It could be shifting behavior. Not user shifting behavior, but what Travis was describing earlier: the 7AT rarely if ever over-revs between gears on upshifts. You click and the revs snap down instantly. 6MT guys are seeing the revs spike a bit before dropping. Given that (as Travis noted, and I agree) the rise in oil temp seems to be affected exponentially by a rise in RPM, this extra time at higher RPMs near the top of the range could be having more effect than you'd expect.
3) User behavior, meaning that basically 7AT drivers drive like grandmas relative to how the 6MT guys drive. In the sense that almost all people who are tracking the car will buy 6MT this is definitely true on average. That aside, even on the street, most 7AT buyers are AT-type of people, and they just drive different, and will often use 'D', which keeps revs *way* down when you're light on the throttle, much lower than where I manual driver would usually hold them at light throttle. However, this isn't the case for me. I just came from spending 10 years behind a 6MT transmission, and I drive my 7AT as close to how you'd drive a manual as possible, and while I'll never approach full track conditions on the street (especially on the braking side of the equation), I'm running the car pretty aggressively.