Quote:
Originally Posted by g20beam
Just caught up reading all the responses on this thread, just want to clear up some questions and concerns:
The B46D is in all 330’s in NA, including my very own after checking the VIN. The quality of the B46D is the same as the B58, same compression ratio, same cylinder bore diameter, etc. The only difference is that it has SULEV parts installed on it in order to meet emissions requirements. The upgraded B48TU is used for stock 300+hp vehicles produced by BMW. This upgraded engine is made to push 300hp even while running lower than 91/93 octane. It is made so that while running low octane, the engine will still be able to make the same power. We can see this because of the lower compression ratio which is found on the engine. It has very little to do with reliability of engine, it has everything to do with gas quality, however.
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Thank you for this.
So the G20 330i, no matter where in the world has the B48D, which BMW didn't seem comfortable tuning to 300 HP or they would have used the same B48D in BMW vehicles producing 300HP instead of up-rating it to the B48TU, is that correct?
As you say, this is probably related to the fact that they have to account that certain regions don't have access to 95+ RON so to achieve that 300 HP stock on potentially lower octane fuels they had to dial down the compression to avoid knock / det - makes sense.
So again, tuning the B48D to 300HP is probably OK if you have access to 98+ RON fuel, don't live in a very hot climate and don't track your car.