When I got my car it didn't have an owners manual. Should I put 87 or 89 in it for now. 98 EX.

 

go 4 the gold,,, u have some mods ,,so treat im right ,thats just my opion,, is a v tek? if so 91-92-93 4 sure,,

 

Yeah, its vtec. I don't know if going up to 91 or 93 would be a waste of my money for what I have now. So, maybe 89,91?

 

just get the 87. octane is a measure of a fuels resistence to detonation, which means it burns slower, which also means that if you dont need the resistence to detonation (you dont) then it isnt giving you any power, and more than likely hurting it.

 

+1, buying a higher octane fuel isn't gonna do anything for your stock motor. The higher octane usually has some detergents to clean your injecters and stuff, but you can get injecter cleaner or have your injecters professionally cleaned once in a while instead. If you advance the timing or get major mods, then higher octane fuel will help reduce detonation but on a stock motor it isn't gonna do much of anything for you.

 

exactly, higher octane has nothing to do with increased power, its mearly the fuels resistance to detonation. When someone says they use 93 octane and their car pulls alot harder I know they have no idea what they are talking about.

 

In addition to what the moderators are saying, running rich sometimes wont let you engine run at its full potential or efficiency. It can make parts like your spark plugs go out a lot faster, the deposits they collect from a rich fuel makes them crappy. Just a little tid-bit of info, the leaner you run, the more HP, the richer you run the more TQ, you should try and find the best spot in between for your car. IMO you should stick to regular 87, nothing higher than 89.

 

My manual says 95 minium.

 

I lived in europe for 3 years... your octane ratings are different that ours.

 

How much of a difference?