Can using "B" cause an increase in oil consumption?

this is a great question! i'll be interested in the responses. all the best!

 

Since the use of "B" requires the gasoline engine to spin faster than otherwise would be required, it would not surprise me if engine oil consumption was accelerated.

 

Doesn't B create high vacuum too, sucks oil up into combustion chamber?

 

It might, depending on what the programming does with throttle position (and possibly valve timing?) while the engine is being spun in "B". One could tell by looking at MAP (manifold absolute pressure) with a ScanGauge while descending a big hill in "B". (Low pressure = "high vacuum.")

In a more conventional vehicle, in which releasing the accelerator closes the throttle, coasting downhill with the wheels spinning the engine and accelerator released definitely results in high manifold vacuum that can increase oil consumption by a leaky engine.

 

Using B will cause engine to revs and create high vacuum. That’s only way it can create engine braking. Valve timing could be used to limit the vacuum but it would also limit the engine braking. High revs and high vacuum will always cause oil usage. If your engine is worn it can use lots of oil while doing this. But it won’t create much wear so as long as you keep the oil level up it really doesn’t matter.

And besides you really have no other option. Not using B will cause more wear on HV-battery, brakes, and even brake failure and accident.

 

I use "B" often but not for a long period of time and have not encountered that problem.

 

I'll check ours and report. Got coerced up a local ski hill, Christmas Eve, and was using B pretty much all the way down. Oil was on top mark, will check.