If the factory recomends a minimum octane use it. They make the requirement based on the tune of the engine, the computer can compensate by pulling timing but only so much.

If the computer can not pull enough timing you risk cracking ring lands.

Our 01 Jetta VR6 needed premium.

If you put in regular it HAS to knock on it before it retards the timing advance.

God that thing was clean.

No doubt it was a beautiful car. Its to bad we had to give it away after my dad passed away. I'd have assumed the payments, but couldnt afford 2 cars at the time.

89 and 87 make the stark difference in terms of knocking for me... I'm too lazy to retard timing and lose power now that winter is over and it'* getting warmer (yes, I have a distributor) - where I used to knock like a bitch just trying to hold 70mph on a slight incline at 10 degrees C outside, I can practically floor it with zero knock. 2 octane points did it.

MPG study with the 89 octane coming soon.

Handdrumman is into V-Dubs. Not sure if he'd know....

i work on them all the time you need to use premium
had a van with 87 in it, ran 3 degrees of kr.
it had no power for somereason. we changed the fuel filter filled it up with a tank of premium and it ran good for some reason.