I haven't heard that. I think many hear the word "GM" and come to biased but unfair conclusions. What problems either brand had could be blamed on BMW's "lifetime fluid" stupidity.
That's not an "either or" question.
The common wisdom is that your should change it. I did my GM's fluid at 90k miles. I've got 120k miles now and no problems.
IMO, anything over 6 is overkill, at least for the US where speeds of over 80 MPH are rare. Marketing "I got more" games, I suspect.
I imagine these silly 8-speeders are *constantly* shifting.
An ideal gearbox would be constantly variable. Sadly practical implementation of such devices is flawed.
With a decent box how would you know or care?
When the E39 came out, certain versions had a GM 4 speed in the US, but a ZF 5 speed elsewhere. Given the 5 speed was so much better in performance and economy, I've never quite found out why.
'Common wisdom' says engines should also have 3000 mile oil changes too.
BMW probably used the older 4 spd GM trannies to save money.
That was true for old school "dino" oil. With today's synthetic, most recommend changing synthetic oil and filter every 7000 to 15000 miles depending on driving condition. Good luck!
Given they don't import their base models to the US, it seems unlikely.
Well, if the same improvements were made to ATF - why not a lifetime fluid? It doesn't get contaminated in the same way as engine oil.
Wait, didn't you just say "When the E39 came out, certain version had a GM *4 speed in the US*" So, I took that saying BMW did export the GM
4 speed auto trannies to the US.Agree, today's transmission fluids are likely synthetic as well. I also agree that tranny fluid probably doesn't get as contaminated as engine oil. Nevertheless, it does get dirty, albeit as a slower rate, so there still should be changing intervals, not just "lifetime." You gave an example of changing your auto trans fluid at 90K. If that is the correct timeframe, then that is what BMW should specify. Eliminating fluid changes by calling it "lifetime" or placing things like fuel filters into the gas tank next to the fuel pump only increases the cost of ownership and doesn't help those who like to keep their cars for more than 100K miles. Then again, BMW's motive is pretty clear they wants you to get rid of your car by then and buy another. Good Luck!
I said they fitted the GM 4 speed to US cars while Europe got the 5 speed ZF. And since BMW have a rather more upmarket position in the US than elsewhere, it seemed a strange move. Unless it was something to do with 'local' content.
Which has absolutely nothing to do with the point I was making about the durability of the transmissions.
The GM in my E46 is a 5-speed, BTW.
Shifting-around is a drawback of autos in general, and one reason some people prefer manuals.
I don't like shifting at the slightest change of conditions. I like to hear my motor swing through some RPM's, not just sit there while the gear ratio is changed.
People are allowed to dislike things that are "better on paper".
Many people despise the "ideal on paper" continuously-variable transmissions, just on the basis of the feel and sound. Even if was
100% efficient and lasted forever, I wouldn't want one.
No, it really doesn't. Almost no one does that. Even in the old days, few did that.
One would intuit that over many years and miles, sufficient contamination and degradation would occur to any practical lubricant.
The GM 5-speed that BMW used was made in France. Not sure about the
4-speed.
Yes - GM eventually caught up. Sad considering they made the finest autos in the world at one time.
I don't think it's that simple. Resale value is something that car manufacturers like to brag-about, and $5,000 trannies breaking every
100k miles (only a few years, for some drivers) can't be too good for that.
Can't see the point of revving the engine under light load. Under heavy load a decent auto hangs on to the low gears just like you'd do in a manual.
Me neither.
Plenty of other parts of a car are lubricated for life. Unlike some years ago.
Yes, but that lifetime is that much shorter.
The problem with chassis bushings that need periodic greasing, for instance, is that people don't actually do it. If you grease them regularly, they will last a whole lot longer than the modern prelubed bushings. But people don't, so they fail prematurely. Same with U-joints. Same with repackable wheel bearings.
So, given the environment the car is used in by the average owner with regard to maintenance, the lifetime lube winds up giving extended life. But in the hands of someone careful, the lifetime lube results in reduced life.
Oh, well.
--scott
"Boy Racer Syndrome"
Remember, his other car is a Supra...
Far too broad a statement.
So 'if people don't do it' why the down on long life lubricants? Seems they are the answer for the majority.
I'm not convinced components which needed regular greasing lasted longer anyway. There's always the chance that greasing will introduce some form of contamination in practice as well as new grease.
Indeed.
All I know is in my experience, modern cars are way more reliable than those of my youth. And the things that fail most on my BMW aren't actually parts that would once have been greased.
Oh, come on. How many control arm bushings have you gone through?
--scott
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