BMW 328i @ 240°
#1
BMW 328i @ 240°
I recently visited my brother in another state, and we took a little day trip in his 2009 BMW 328i. I did the driving, and I noticed the temp gauge was marked in degrees Fahrenheit and that the running temp was 240° (just below the 250° mid-point on the gauge).
Presuming the gauge was accurate, I wondered why 240° is okay for that engine and not okay for the Rover V8 in our trucks.
Your thoughts, please?
Presuming the gauge was accurate, I wondered why 240° is okay for that engine and not okay for the Rover V8 in our trucks.
Your thoughts, please?
The following users liked this post:
whowa004 (07-09-2023)
#3
Its not ok for the BMW either. They don't give two ****s about engine longevity as long as it makes it out of the warranty period. In fact, BMW engineers take the view that the engine/car is ready for retirement once it reaches 100k. At that temperature the oil is very thin and even a minor cooling system excursion results in a blown engine. Guys on the BMW forums are starting to figure it out as they approach high mileage and are getting pissed. BMW runs them that hot to maximize fuel economy and emissions by intentionally thinning out the oil, but no one wants their race car at that temperature. People will say "the engine was designed for it" . By the same dumbass engineers that put the bypass thermostat in the D2, the plastic crossover pipe at the rear of the heads on a RR, timing chains at the back of an audi, and the disasterous timing chain tensioners on the BMW 4.4. Just because they are engineers does not make them infallible, and their motivations are much different than yours.
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@mln01 The gauge on the F30 BMWs (The 2009 328i is an F30) shows oil temp, not coolant temp. Under normal driving conditions it should run between 230 & 250. (I have owned four BMWs) It is annoying they run them that high since SAE rates oil viscosity at 212 degrees, but, that's what BMW intended.
Last edited by L33DiscoII; 07-10-2023 at 11:27 AM. Reason: clarity
#7
Was reading an SAE paper yesterday on timing chain wear compared vs three oil types, mineral, semi-syn, and full syn. Full syn had half the wear rate of the other two, and we know mineral and semi-syn do not have the same temperature resistance as the full syn. Full syn only on those DOHC engines guys.
#8
Found this - For a dual-purpose car, engine oil needs to be at least 220 degrees F to burn off all the deposits and accumulated water vapor. For every pound of fuel burned in an engine, the combustion process also generates a pound of water! If engine sump temperatures rarely exceed 212 degrees (water's boiling point), the water will mix with sulfur (another combustion byproduct) and create acids that can eventually damage bearings. As for ultimate power potential, the general consensus among most racers is that hot oil and cool water make more power in most engines. Cold engine oil causes excessive frictional drag on the bearings and cylinder walls. A quality conventional motor oil will tolerate oil sump temperatures up to 250 degrees, but starts breaking down over 275 degrees. The traditional approach is to try to hold oil temperatures between 230 and 260 degrees. Even on a short-duration, drag-only combo where oil is frequently changed, you would not want to routinely see oil temps under 200 degrees.
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@mln01 The gauge on the F30 BMWs (The 2009 328i is an F30) shows oil temp, not coolant temp. Under normal driving conditions it should run between 230 & 250. (I have owned four BMWs) It is annoying they run them that high since SAE rates oil viscosity at 212 degrees, but, that's what BMW intended.
I feel dumb. Every time I would tell him “your car runs really hot!” Haha
The following 2 users liked this post by arains44:
L33DiscoII (07-11-2023),
V50-M66 (07-11-2023)