[T_U_D]

As always top notch info from Savagegeese.

[Chet for short]

I'm still under 600 miles. It's agonizing to keep it under 5k and no WOT. Kinda like 'just the tip'

[tylerdurdem]

My car had 58 miles on it when I got it with an average fuel economy of 12mpg, so I'm guessing break in procedures were already not followed by the time I bought it. My break in philosophy is basically don't track it and try to keep it under 6k rpm (which I've not always managed to do, 1st is quite short in the ZF8), and WOT is just going to happen sometimes. I figure if it were that important, there would be a soft rev limiter until break in service is complete. We'll see if I regret it.

[Ma_Deuce]

Originally Posted by tylerdurdem

My car had 58 miles on it when I got it with an average fuel economy of 12mpg, so I'm guessing break in procedures were already not followed by the time I bought it. My break in philosophy is basically don't track it and try to keep it under 6k rpm (which I've not always managed to do, 1st is quite short in the ZF8), and WOT is just going to happen sometimes. I figure if it were that important, there would be a soft rev limiter until break in service is complete. We'll see if I regret it.

Fully agree, the car already has a soft rev limiter on it, check your rpm gauge when you cold start the car, the yellow and red is lower than when warm.

[Fastfwd]

Watching that video makes me wonder if there may be increased concerns for taking delivery during the winter months? If perhaps it might be better to try to avoid driving on the coldest days at least when possible? Would these 'thermal shocks' he mentions be more concerning if the operating temperatures were brought up too high and then left to sit in freezing temperatures or would even normal operating temperatures produce enough of a 'thermal shock' to potentially be damaging?

I might guess that it would be ideal to park it in a temperature controlled garage to mitigate those thermal shocks during the winter months of break in, but that's not going to be possible.

[RockCrusher]

Originally Posted by Fastfwd

Watching that video makes me wonder if there may be increased concerns for taking delivery during the winter months? If perhaps it might be better to try to avoid driving on the coldest days at least when possible? Would these 'thermal shocks' he mentions be more concerning if the operating temperatures were brought up too high and then left to sit in freezing temperatures or would even normal operating temperatures produce enough of a 'thermal shock' to potentially be damaging?

I might guess that it would be ideal to park it in a temperature controlled garage to mitigate those thermal shocks during the winter months of break in, but that's not going to be possible.

You are over thinking this.

In cold weather -- in some cases down to 0F -- I just follow the same cold start/cold driving procedure I use in warmer temperatures. Keep RPMs down below some upper threshold. I see nothing specific in my M2 manual but I recall from my Porsche days the upper limit was 4200 RPMs. I kept RPMs below 4K -- actually not much over 3K -- just for a bit extra "safety" margin.

I continue to keep RPMs below 4K and engine loads reasonable until the coolant temperature gauge has reached a point I know the engine is fully warmed up. However, with just a coolant temperature gauge one has to allow for the fact oil temperature from cold lags coolant temperature. So I'd give the engine another 15 minutes of run time after the coolant gauge indicated the coolant was up to temperature.

But the M2 has an oil temperature gauge so I just wait until that indicates the oil temperature is at "210F". (See attached pic.)

The M2 oil temperature will get to 210F in a reasonable amount of time even if the ambient temperature isn't 100F...

As has been my habit for years if I have been driving a car at high speed -- like on the freeway -- I will give the engine some time to shed some of the heat load it has before I turn the engine off. My 996 Turbo owners manual called for a 2 minute idle time to give the turbos time to shed some heat before shutting off the engine. Exhaust valves too. These run quite hot. While the engine is idling and the exhaust gas is of course hot it is quite a bit cooler than when the engine is running at say 3K RPMs. And this cools the turbos and exhaust valves so the turbos don't "cook" the oil in their bearings and the exhaust valves don't "cook" the oil in their guides.

I see no such recommendation in my M2 owners manual. (But I believe the M2 turbos are water cooled.) And most of the time after I leave the freeway I have to drive several miles on surface streets before I reach home. Thus the engine, turbos, and exhaust valves have had time to shed some heat load but even so after I get the car in the garage I let the engine idle a bit, ~30 seconds, because well just because old habits die hard.

[Fastfwd]

Originally Posted by RockCrusher

You are over thinking this.

In cold weather -- in some cases down to 0F -- I just follow the same cold start/cold driving procedure I use in warmer temperatures. Keep RPMs down below some upper threshold. I see nothing specific in my M2 manual but I recall from my Porsche days the upper limit was 4200 RPMs. I kept RPMs below 4K -- actually not much over 3K -- just for a bit extra "safety" margin.

I continue to keep RPMs below 4K and engine loads reasonable until the coolant temperature gauge has reached a point I know the engine is fully warmed up. However, with just a coolant temperature gauge one has to allow for the fact oil temperature from cold lags coolant temperature. So I'd give the engine another 15 minutes of run time after the coolant gauge indicated the coolant was up to temperature.

But the M2 has an oil temperature gauge so I just wait until that indicates the oil temperature is at "210F". (See attached pic.)

The M2 oil temperature will get to 210F in a reasonable amount of time even if the ambient temperature isn't 100F...

As has been my habit for years if I have been driving a car at high speed -- like on the freeway -- I will give the engine some time to shed some of the heat load it has before I turn the engine off. My 996 Turbo owners manual called for a 2 minute idle time to give the turbos time to shed some heat before shutting off the engine. Exhaust valves too. These run quite hot. While the engine is idling and the exhaust gas is of course hot it is quite a bit cooler than when the engine is running at say 3K RPMs. And this cools the turbos and exhaust valves so the turbos don't "cook" the oil in their bearings and the exhaust valves don't "cook" the oil in their guides.

I see no such recommendation in my M2 owners manual. (But I believe the M2 turbos are water cooled.) And most of the time after I leave the freeway I have to drive several miles on surface streets before I reach home. Thus the engine, turbos, and exhaust valves have had time to shed some heat load but even so after I get the car in the garage I let the engine idle a bit, ~30 seconds, because well just because old habits die hard.

Appreciate the input. I've just never heard the mention of 'thermal shock' used in relation to break in. I can't imagine more of a 'thermal shock' than bringing a vehicle up to temperature and then it being exposed to some of the bitter cold windy days that we get where I live. Certainly, some places have much more bitter cold weather. Granted manufacturers have to take into account that this is inevitable and unavoidable in some cases.

I may at least try to observe ambient temperatures during the break in period. It may give me reason (or excuse) to push through the break in period while the weather permits me to do so without the potential of bitter winter temperatures impacting the break in.

I've been more into my home stereo equipment in recent years and there is a parallel debate on philosophy of just leaving your stereo electronics running 24/7 instead of turning them on and off. Those components are believed to suffer more from cycles of heating up and cooling off than maintaining a consistent temperature. Some argue heat kills electronics period.

I've sort of adopted a hybrid approach. In the winter months I do leave my components on 24/7. The ambient room temperature can get a bit chilly at times so I just let the components stay warm and know they won't really 'overheat' from it. In the summer I tend to turn them off and/or run a fan to circulate air if they are left on.

I think that may be the reason I'm more sensitive to hearing the mention of 'thermal shock' as it pertains to the engine during break in.

[RockCrusher]

Originally Posted by Fastfwd

Appreciate the input. I've just never heard the mention of 'thermal shock' used in relation to break in. I can't imagine more of a 'thermal shock' than bringing a vehicle up to temperature and then it being exposed to some of the bitter cold windy days that we get where I live. Certainly, some places have much more bitter cold weather. Granted manufacturers have to take into account that this is inevitable and unavoidable in some cases.

I may at least try to observe ambient temperatures during the break in period. It may give me reason (or excuse) to push through the break in period while the weather permits me to do so without the potential of bitter winter temperatures impacting the break in.

I've been more into my home stereo equipment in recent years and there is a parallel debate on philosophy of just leaving your stereo electronics running 24/7 instead of turning them on and off. Those components are believed to suffer more from cycles of heating up and cooling off than maintaining a consistent temperature. Some argue heat kills electronics period.

I've sort of adopted a hybrid approach. In the winter months I do leave my components on 24/7. The ambient room temperature can get a bit chilly at times so I just let the components stay warm and know they won't really 'overheat' from it. In the summer I tend to turn them off and/or run a fan to circulate air if they are left on.

I think that may be the reason I'm more sensitive to hearing the mention of 'thermal shock' as it pertains to the engine during break in.

BMW has provided for a cooling system that helps bring the engine up to temperature while avoiding excessive temperature gradients. Thus the chance of any real thermal shock is greatly reduced. Honestly I wouldn't worry about it. Just adhere to gently using the engine while it is coming up to temperature. Doing that plays a pretty big role in avoiding sudden spikes in temperature and excessive temperature gradients.

Do this during break in and after.

[Geighty7]

Question- just got my car yesterday. Is downshifting to slow down and hitting 3.5k on the rpm with the auto rev match on for the new engine?! I love the feeling and sound, trying not to hit 4k.

[RockCrusher]

Originally Posted by Geighty7

Question- just got my car yesterday. Is downshifting to slow down and hitting 3.5k on the rpm with the auto rev match on for the new engine?! I love the feeling and sound, trying not to hit 4k.

Bit late to respond but as long the downshift doesn't have RPMs go over the break in limit of (IIRC 5K up to 600 miles 6K RPMs up to 1200 miles) my (non professional) opinion is there is no harm. I note there is no caution in the owners manual on this subject.

I do know from experience the rev match makes for a smooth downshift so that's a plus.