Reccomended octane not at the pump

[TrailRatedRN]

Know there are tons of gas threads on here, but I have a bit of a different question. If the manufacturer's suggested octane rating is not available at the time of fill up, is it better on the engine to go up or down in octane rating?

My gas cap recommends 91, but the gas stns by my house offer 89 and 93. I assume that going to the next highest octane would provide the most stable firing environment, but I'm no expert and would prefer to not waste my money if I'm thinking wrong.

 

[mud4feet]

This is totally a personal preference, but I go with the cheapest stuff......I dont think 2 points in octane make a bit of difference unless youre running NASCAR. My jeep has 188,000+ miles on it and it has served me well. If I were you, I wouldnt waste the money.

 

[JPNinPA]

If your engine has a turbo it likely needs the higher octane. If you run lower octane the engine will knock and the PCM with adjust the fuel air ratio to eliminate the knock. So you'll end up burning more gas. You can pay more for it now or pay more often for it. It is your choice. Was this a jeep question?

 

[TruckProUSA]

You could do half and half I'm no chemist, but seems like maybe it would work? haha Octane is also dependent on elevation. Looks like you're in Ohio, so that's not an issue. When you're lucky enough to visit Colorado, you'll notice a lot of pumps with 95 available. Anyway, if I were in your shoes and that was the only gas choice, I'd go up, rather than down. The science nerds at Chrysler have set up your engine to run properly at the suggested octane level. Neither one will make it run optimally, however, going down at low elevations is not something I'd want to do. Probably knock. There's my non-chemist, non-legally-binding opinion