I live in Colorado, and i have heard this from many a dealership and mechanic....when you are at 5280 ft don't use premium grade in a NA car because it will burn your valve stems off. you can use mid if you want but the dealers here recomend low grade which is 85 octane here mid is like 87 and premo is 91....the nice thing about the alt is you can get away with running a turbo or S/C car on mid grade but i still recomend premo as long as you have a good FMU.

 

i was thinking about putting techtron in my car the next time i fill my gas up. techtron is product that cleans out the fuel injectors. does anyone know if this is needed because i heard that the fuel injectors should be cleaded every 5000 miles with a fuel additive?