Fuel Mixture

Since the first day I bought my 2005 Mazda 6i Hatchback I have been putting 91 Octane (Premium gas-CA) and some people are telling me that all I need is 87 Octane (Regular gas - CA) because putting 91 Octane on Non-turbo Mazda 6's tend to lose power, is this true?

If yes, what are (will be) the effects that my car will go through if I downgrade from 91 octane to 87 octane.

Nando 6i said:

Since the first day I bought my 2005 Mazda 6i Hatchback I have been putting 91 Octane (Premium gas-CA) and some people are telling me that all I need is 87 Octane (Regular gas - CA) because putting 91 Octane on Non-turbo Mazda 6's tend to lose power, is this true?

If yes, what are (will be) the effects that my car will go through if I downgrade from 91 octane to 87 octane.

Click to expand...

Look at the link

haha...link?

i don't think it's a big loss of power, but over time, since the engine isn't designed/tuned for the higher octane, it will tend to leave unburned deposits in the engine that can rob power. also, since not all the fuel is used, you don't take full advantage of the cumbustion in the chamber and tend to loose some performance.

unless you are tuned for it, i'd stay away from 91 and go back to 87. use the $ ou save on a treatment of fuel system/injector cleaner to help any buildup that MIGHT have gathered due to the 91.

I really don't think it will kill the engine by any means, but there aren't any advantages that need you to continue with it.

yeah 91 burns slower than 87 and results in shotty MPG. It's designed for cars tha need to run off it or engine goes boom. Just cause it says Premium, doesn't make it caviar for cars. I blame marketing, mostly Shell for these rumors and their V-Power adds. Also think of it as saving money cause you don't have to buy the expencive gas. don't beleve me sit down and calculate how much it takes to fill up on 87 and then 91. $0.20 isn't really that much till you add it Xs 18 yeah I'd burn it down to the light and run a few bottles of cheveron with techron for next few tanks.