Originally Posted By: Neenos76
Skyship, you're right condensation won't cause tbn to drop. It's the interaction of gasonline, EO, and metals that cause acidity build up. There is truth to short trips being bad for the car. If the EO doesn't get up to operating temperature the gas that slides past the rings will sit in the oil pan. Over time this will break down the EO and create larger acid values. I'd be more worried about condensation in the gas tank.
Thanks for that, as my background is very diesel orientated and the chemistry involved is very different, as is the fuel quality in the US. The question is why do only a few manufacturers of petrol engines say 6 months, although it's rare to see a 6 month warning for a petrol car sold in the EU. My guess is that US dealers want owners to return more often.
I suppose the important factor with fuel contamination is engine age or condition combined with time at idle, as older engines (Might be worn injectors in many cases)that spend too much time at idle sometimes show fuel contamination, with the old big blocks top of the list.