I was wondering if I could use the low octane fuel and not the high dollar premium gas in my 94 940 Turbo wagon ... what are the risks in using the lower grade?

 

In theory, you should be fine. The knock sensor should have the icu pull timing when you're in boost and the panther **** low octane causes detonation. In practice, detonation can still occur as the turbo crams extra fuel/air into the combustion chamber. Detonation is not a good thing for turbos; it can cause broken spark plug ceramics, melted piston crowns, bent connecting rods and other inconvenient things. If you can't afford the extra $5 a tank for premium, you could try to squeak by on mid grade but keep your ear open for rattling and pinging. If you hear it under boost immediately get off the gas and add premium. If you never run boost, you can run regular all day long...but if you drive like that, why on earth would you have a turbo?