Fuel type question

[JAYISK]

Hey Guys,
with petrol prices on the way down I'm just curious, is there any benefit of me running the high octane fuel in my 8v GTI?

I normally just put in regular unleaded and never E10 as I have heard horror stories.

Any insights?

[h100vw]

Not sure what the compression ratio is on those RV motors but I'd still use 98 myself. With a bit of careful playing I am pretty sure you can bump the timing off the dissy to get the best from it.

Gavin

[The_Hawk]

Personally I've always stuck with premium/98 through all my cars.

In the old days I did some testing to see if it was worth it and found that in the worst case I would break even. I'd always get extra km out of a tank of 98 but at higher cost to full up.... but like I say it averaged out to be break even $$ wise. Any added power or cleaner running was considered an extra bonus. I also found that I got better benefits when on a trip than around town milage wise.


If you don't already, jump onto fuelly:
Fuelly - Track and Compare your MPG

[sports racer]

Using higher octane petrol doesn't give you more power.

High octane petrol is formulated to prevent detonation in high compression engines. The engine doesn't produce more power because of the higher octane petrol but because it has higher compression it squeezes more petrol in which gives a bigger bang every time it's ignited on the power stroke. Bigger bang = more power.

If you're running high octane petrol in your low compression engine then the only benefits are the extra cleaning agents in the petrol. You may also be able to advance the timing on the MK2 more than you could with 91 octane but for the extra cost of the petrol it's hardly worth it.

I ran 91 octane on my MK2 for years, when it was a 1.8 and when it was a 2.0. It didn't need any better because it doesn't have high enough compression for it not to run on 91 octane.

E10 is corrosive and will eat the rubber seals on old cars. It's OK for new cars because they are built to suit the E10. Never run it in an old car.

Cheers

Paul

[ryana89]

I have a bad habbit of not driving my MK2 for months at a time, the 98 lasts that little bit longer/better for me.
Maybe you could let us know, see if you actually get better/worse economy driving on 98 or 91?

My best on 98 was 5.5L/100km on the pacific highway

[JAYISK]

I filled up last night with BP 98.
I'll test it and let you guys know how many km's i get on a tank. I'll have run a few tanks to get an average. If anything I hope it cleans out the engine