3-Series (E46, E90)Chat relating to the BMW 3-Series from 1999 to Current. Models include: BMW 316i, BMW 318i, BMW 318Ci, BMW 320i, BMW 323i, BMW 325i, BMW 330i, BMW 328 Ci, BMW 328i, BMW 325i/xi, BMW 330Ci, BMW 320d, BMW 330d, BMW 335d.
I will make sure to get some pics up as soon as possible. I bought a 01 325i sedan a little over a week ago. It is a manual transmission, and I've noticed that at 70 mph the rpm's seem to be noticeably higher than my dads 04 automatic tranny. At 70 my rpm's are around 3000. I'm assuming this is normal, however, how high of an rpm can these engines maintain without damage? I'm guessing that at a speed of 80-85 mph I would be looking at around 4000 rpm? I've been trying to figure out what is an acceptable rpm to be driving at, shifting at, etc. I'm sure in the future I will look back at this post and laugh, but I haven't been able to find much through google searching. Any info would be greatly appreciated. Also, is there a way to tell by VIN number, what options came from the factory? I am having a tough time finding another 01 anywhere online with the same options to compare it to. Thanks in advance!
Your car has a 1:1 gear ratio in fifth gear (I assume you're in fifth gear when you are going at 70 mph), whereas your dad's car (sure it is not a 330i?) has an overdrive gear with a 0.74 gear ratio for fuel economy, which translates to lower rpm at the same speed, despite the higher final drive ratio on the auto. The auto has a final drive ratio of 3.46, whereas the manual comes with a 3.15 unit.
I shift at no higher than 3000 rpm when the car hasn't warmed up (I let the tem gauge point to 12 o'clock, then I wait 5 minutes). After that, I shift at whatever engine speed fits the mood. Be sure to redline your car every so often - that is what it was meant to do. I have two 3 series BMW's with the inline 6 engines, and I drive them the same way. These cars are meant to be fun (the 218,000 miles on the odometer of my E36 are a testimony to that).
I just thought of another question. Even though the gearing ratio's are different, the engines are obviously the same. I would assume that most manual owners would be driving and shifting at higher rpm's than the automatic tranny shifts at. Has anyone observed engine life or performance differences over time between the two?
I really don't think anyone would ever see an actual difference in a given engine model's life by a transmission difference alone. The driving style and service to the engine would be by far the determining factors. A harsh driver can abuse an engine with an auto as easily as with a manual.
I'm sure that's right. I guess I was thinking about a few of the earlier posts about running the rpm's up periodically, and assume that that there are many 325 owners with automatics that never really do that...like my dad.
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