What are the major differences between these two engines? Why did Volvo start using the B230F in the 240 for '85? I've heard that they are essentially the same, and then I've heard that they are essentially not alike at all. Have also heard that the B230F is made of lighter, less expensive components. My B23F had 240K on it when it died-what is the average lifespan of the B230F? The one that I dropped in has almost 150K on it, and it is still very strong (much stronger than the B23F ever was). I floored it once to get out of the way of an idiot that forgot to turn on his lights (turned out right in front of him because I didn't see him coming!) and scared the hell out of myself-I actually chirped the rear wheels in 1st gear! Couldn't do that before! :-)