Rep Power: 0

whats good and bad for my 2003 EX fuel wise? i have about 57k on it and its a manual...ive been switching just about everyother fill up from 87 octane to 89 octane and the manual says nothing lower/high than 86 octane...what would be the best for my engine?

Thanks

 
Rep Power: 253

if the manual says nothing lower then 86 I would just run 87

 
Rep Power: 0

ok, so does that mean that 89 is bad for the engine? not like killing it right away but in the long run? im just wondering bc my gf has a Jetta 1.4l turbo and that takes the super stuff..the 91 octane i think is the number but she puts 89 sometimes..so is it bad for me to put the 89 in?

 
Rep Power: 266

89 octane isn't bad for the engine, there are gas stations that don't sell anything lower than 89 octane. you really only have to worry about harming the engine when you put a lower grade fuel in there than what is required in the manual.

 
Rep Power: 0

ok sounds good! thanks

 
Rep Power: 291

stick with what is recommended in the manual. the jetta is TURBO, and needs higher octane. your civic isn't, and doesn't.

 
Rep Power: 306

done and done.

also straight answer from everyone else as well