Does Higher Octane Gas Matter?
 

The VW Jetta that I'm selling I bought off a friend who builds VW's for a living. He told me never to use anything about high octane gas at least 91 in octane... so that's what I did...

Since I'm going to be buying a new Protege... I wanted everyone's opinion here... Does it matter? It only costs like $2.00 CDN extra per fill-up to get the higher octane gas...

I hear different stories from different people.. what's the true verdict on its benefits?

PJStyles

This has been discussed before.... but we have found that using regular 87 octane (or 89 i think) is all that is necissary for our p5s. If you know much about gas, really all the higher octanes are is larger molecules that need to be broken down, thus resulting in a power loss if you dont need that octane....correct me if im wrong on that.

I just want to make sure I'm doing everything I can to maintain this Protege the second I get it... It'll be my baby :) Also, we need to get more members on this board... on the VW forum I'll post a message and I'll get like a half dozen replies within minutes :)

PJStyles

ya i hear ya bro.....

take care of that baby, she is a great car :D oh and im one who will say: stay away from ethenol crap.... bad gas.... lol

once you get your P-5 look at the manual...is specifically tells you that you only need REGULAR unleaded gas...it will also tell you NOT to use ANY gas/alchol mix that has more than 10% alcohol and if you can totally avoid it...DO SO!! there have been some members that have actually noticed a performance DECREASE by putting in the highest octane all the time...even gas mileage has dropped off. :D

BTW...welcome to our happy home...the fridge is stocked with your favorite cold drinks...flop on the couch...take your shoes off...make yourself at home. :D

car will run fine on 87, but the engine run quieter with 89 IMO

So are you saying we should use 89 Octane then?

PJStyles

I used 89 a couple of times when I was in New Mexico. Really didn't notice a big difference either way. Mileage slipped ever so slightly. They only sell 86 octane up there and I was weary about putting something lower than 87 in my car. I've never noticed an obvious reason to spend the extra dough.

well it was winter here and the car was running better with 89

I thought it was always winter there? :) It's already in the frickin 90's down here. Even worse if you go a little further west.

when I use 89 my car runs quieter and also responds better with less hesitations and so forth , I have an intake , muffler and advanced timing , so I tend to run a higher octane, simply cause i can notive the difference . I honestly despise regular gasoline, even though it is so cheap ,.. mainly cause I feal that the engine can have better characteristics , when using a hgher octane feul , but this also depends on your mods
Bruce

No Proteges have knock sensors. G3's have non-adjustable timing. If it doesn't knock on 87 octane, don't bother using anything higher.

My Pro has started knocking a bit on 87 octane, so I use 89.

If it's not advanced enough to knock on 89 octane, there is no reason to use 91. With a low-compression, fairly tough N/A motor (like a Pro engine), a little bit of knock will not hurt anything. We are not talking about turbo rotaries here :D

87 All You Need In A P5
 

It has been advised by Consumers Union that using higher grade fuels than is called for in the manufacturer's manual is nothing more than throwing your money to the wind. Some (usually more expensive, luxury makes and/or serious performance) cars require premium fuel, but all generation Proteges (I'm not sure about the MP3, though!) are designed to run fine on standard 87. They don't sport a compression ratio high enough to warrant 91 Octane fuel (spontaneous combustion due to high compression; pre-spark plug induced).

As others have said, I wouldn't use anything higher than 87 unless you're noticing pinging difficulties, or unless you've done something funky to the engine. As long as you go with decent quality fuel I doubt you'll have any problems, especially with a brand new car. Save your money for modifications or other improvements to your ride-- Screw rip-off premium fuel!! It's not needed, and it's a waste!

What does this knock sound like? Not sure I've ever heard it.

PJStyles