BMW-525I - oil change frequency

Huw wrote:
>
> Can't see why you would change the brake fluid or particularly the coolant
> every two years. Every fourth year is fine for brake fluid AFAIK and five to
> six years for good quality coolant or at every 60,000 to 100,000 miles or at
> every radiator/pump or other component change.
> Manufacturers usually quote three years for brake fluid [depending on
> territory] and five years for coolant these days.

Well, not BMW. The coolant and brake fluid are called for replacement
every other year per the bi-annual service in their schedule.

-Fred W

"Fred W" > wrote in message
...
> Huw wrote:
>>
>> Can't see why you would change the brake fluid or particularly the
>> coolant every two years. Every fourth year is fine for brake fluid AFAIK
>> and five to six years for good quality coolant or at every 60,000 to
>> 100,000 miles or at every radiator/pump or other component change.
>> Manufacturers usually quote three years for brake fluid [depending on
>> territory] and five years for coolant these days.
>
> Well, not BMW. The coolant and brake fluid are called for replacement
> every other year per the bi-annual service in their schedule.
>
> -Fred W

Yes, BMW are very conservative with all fluid changes.

Huw

"Huw" > wrote
> "Fred W" > wrote
>> Well, not BMW. The coolant and brake fluid are called for replacement
>> every other year per the bi-annual service in their schedule.
>>
>> -Fred W
>
> Yes, BMW are very conservative with all fluid changes.

Uhhh, how do you reconcile that statement with "lifetime"
differential and transmission fluids?

Floyd

"fbloogyudsr" > wrote in message
...
> "Huw" > wrote
>> "Fred W" > wrote
>>> Well, not BMW. The coolant and brake fluid are called for replacement
>>> every other year per the bi-annual service in their schedule.
>>>
>>> -Fred W
>>
>> Yes, BMW are very conservative with all fluid changes.
>
> Uhhh, how do you reconcile that statement with "lifetime"
> differential and transmission fluids?
>
> Floyd

And the "lifetime" coolant as of the 2003 models!

Tom

"Dick Schneiders" > wrote in message
...
>>> Yes, BMW are very conservative with all fluid changes.
>>
>>Uhhh, how do you reconcile that statement with "lifetime"
>>differential and transmission fluids?
>>
>>Floyd
>
> Touche, Floyd, but it really is quite obvious when you look at it from the
> company's standpoint.
>
> They are very conservative about fluids, as long as the car is still under
> warranty. The "lifetime" diff and tranny fluids generally will last, at
> least,
> until the warranty runs out. At that point, BMW no longer cares what
> happens
> to your vehicle. They will be very happy to replace your tranny at your
> cost.

That's about right. The 'lifetime' transmission fluid actually is good for
an average of only 100,000 miles. No doubt the transmission will last a good
while with less than acceptable fluid before it fails. So for most cars it
will last the life of the car. For a significant number of owners though,
the transmission will fail prematurely.
It should be noted that even with a fluid change, the transmission will not
last indefinitely and a small number would still fail prematurely.

Huw

>The 'lifetime' transmission fluid actually is good for
>an average of only 100,000 miles. No doubt the transmission will last a good
>while with less than acceptable fluid before it fails. So for most cars it
>will last the life of the car.

It is only the lifetime of the car because when these trannys fail, because of
lack of fluid changes, the owners often will not want to go to the expense of
replacing it in a car with, say, 150,000 miles. However, these cars will
typically last much, much longer than 150,000 miles and so will many of the
trannys, if given the fluid and filter changes that they should get (even if
they have "lifetime" fluid).

Therefore, it is my feeling that the lifetime of one of these cars would be
considerably longer if the transmission lasted longer. There is no reason that
the life of the car should equate to the life of the "lifetime" fluid.

"Dick Schneiders" > wrote in message
...
> >The 'lifetime' transmission fluid actually is good for
>>an average of only 100,000 miles. No doubt the transmission will last a
>>good
>>while with less than acceptable fluid before it fails. So for most cars it
>>will last the life of the car.
>
> It is only the lifetime of the car because when these trannys fail,
> because of
> lack of fluid changes, the owners often will not want to go to the expense
> of
> replacing it in a car with, say, 150,000 miles. However, these cars will
> typically last much, much longer than 150,000 miles and so will many of
> the
> trannys, if given the fluid and filter changes that they should get (even
> if
> they have "lifetime" fluid).
>
> Therefore, it is my feeling that the lifetime of one of these cars would
> be
> considerably longer if the transmission lasted longer. There is no reason
> that
> the life of the car should equate to the life of the "lifetime" fluid.

For high per-annum mileage, I would agree with you and would change the
fluid at around 80,000 to 100,000 miles but for a car that averages no more
than 12000 miles yearly over several owners then why bother? The
transmission will probably last 150,000 miles or more anyhow with luck. The
same luck that would be needed even if the oil were changed yearly
..
There is no evidence that I know of which shows that regular servicing of
either GM or ZF will increase their average service life at all. This is
speculation on our part.

Huw

In article >,
Huw > wrote:
> There is no evidence that I know of which shows that regular servicing
> of either GM or ZF will increase their average service life at all.
> This is speculation on our part.

I'm inclined to agree. If the design life of a component is a minimum
100,000 miles say, then a lightly loaded one will last longer - perhaps
much longer. And those that are doing high mileages suggest a lot of
highway driving where the load is low.

--
*I'm not being rude. You're just insignificant

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" > wrote in message
...
> In article >,
> Huw > wrote:
>> There is no evidence that I know of which shows that regular servicing
>> of either GM or ZF will increase their average service life at all.
>> This is speculation on our part.
>
> I'm inclined to agree. If the design life of a component is a minimum
> 100,000 miles say, then a lightly loaded one will last longer - perhaps
> much longer. And those that are doing high mileages suggest a lot of
> highway driving where the load is low.
>

Even where a transmission fails, it could be because of general wear or
component failure unrelated to fluid condition.

Huw

>> There is no evidence that I know of which shows that regular servicing
>> of either GM or ZF will increase their average service life at all.
>> This is speculation on our part.
>

While there might be evidence somewhere that would satisfy you, I have never
seen any that is definitive. So I mostly agree with you that we are
speculating. However, I would prefer to speculate *and* do regular
transmission fluid/filter changes. They are inexpensive on most of these cars,
and certainly are when compared to a transmission rebuild/replace. I have seen
and heard about many of these transmissions going 200,000, 300,000 miles and
more without any major repairs, and every one of them has had periodic
fluid/filter changes. I have never heard about one with that many miles on the
original fluid/filter. There probably are some, most likely those using the
long-life fluid (I don't use the term "lifetime").

While this probably still does fall into speculation, I like to improve my odds
when I can.

Dick Schneiders