What grade of gas to use??
 

What grade of gas do you use in your protege 5's? I am new to the mazda family. I used to own a VW and always used premium gas in it. Is it recommended to use premium gas in the P5? I know in the manual it says that regular gas is okay? I am hurting anything or getting any benefits by using premium?

thanks
Greg

i use 89 octain....i find the engine run's smother with it especialy in the winter time

I just recently filled up with the highest octane that we have available everywhere, 94 and it runs really smooth. Usually I go for the lowest available because of money hehe, 87 and it's not that great...... Your car won't be any worst off though if you use lower grade fuel.

The Protege's ECU is programmed to keep the engine tuned for 87 octance. It will not recognize higher octane gas and will not tune the engine to take advantage of higher octane gas. I stupidly ran higher octane gas in my Protege. Although it was a tad bit smoother when I first started using it, after a few thousand miles, the car was running slightly hotter and was hesitating. When I changed the spark plugs, they were covered in carbon! With the new plugs and 87 octane, the temperature went back down to normal and there's no more hesitation. 40,000 miles, countless gallons of 87 octane, and another set of spark plugs later, I haven't run into the same problem again!

-Jerry

I remember something in the user's manual for the 2.0L engines saying to use premium. For the 1.5L or the 1.8L it says that it is okay to use regular though...

I was told to run a higher octane

see sig

are you sure the ecu wont take advantage of 94 octane? i thought all ecu's are designed to adjust their fuel maps during regular use. i always put at least 91 octane in my moms 99 protege 1.6, but that is the recommended octane level anyways. when i put 94 octane it seems a lot quicker and i havn't noticed it running any hotter. i just changed the spark plugs yeserday and they were fine, nice and orangey with almost no deposits.

On Page 4-2 of the 2001 Owner's manual:

"Your Mazda will perform best with regular unleaded fuel having a research octane number (antiknock index) of at least 91 [(R=M)/2 method, 87]"

The manual states to USE REGULAR. My car is a 2.0L.

thank you mike, I was gonna go to my car and pull out the manual and quote it, but you saved me some walking time :D

USE REGULAR UNLESS YOU HAVE SIGNIFICANT ENGINE MODS.... :D

LOL! That's exactly what I did....somebody had to stop the insanity!! :D

Look a little bit farther down on page 4-2 in the User's Manual....

It is also on the back of the User's Manual:

Quoted from 2001 Mazda Protege Manual!! BOO-YA!!! :p
Don't believe me, then check it yourself...

I DO NOT have that in my manual.

HAHAHAAHAHAHAH!!!! The part I quoted is actually a STICKER covering up old writing. I flipped the page over so I could read the writing (backwards though) and it's what you are quoting Zeriak. Looks like they had a misprint and changed it in the manual...seems yours didn't get fixed.

HAHAHA! Perhaps you are right. I'll so bet that the 91 Octane is for the MP3 Engine.

Someone get the manual for the 2002 Protege and tell us what it says to use...