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MG MGF Technical - Unleaded or superunleaded?

Greetings everyone,
I am almost ready to purchase a secondhand F, a 1997 VVC in fact. I have aquestion if I may: would I use unleaded or superunleaded? or can I use either or both.
Thanks
Paul
Paul

You can use either.... but the MEMS won't benefit from the higher octane :o(
tim woolcott

You can use either or both, but to be quite honest, you'd be wasting your money purchasing Super Unleaded for your F. The engine management has been calibrated for use with 95 Ron Unleaded. The system has no knock sensor, so if higher octane fuel is used, there is no adaption to exploit this and improve performance.

Best keep to the cheap stuff! <bg>
Rob Bell

I was a little more succinct ... :oP Posted at the same time .... spooky
tim woolcott

ROFL - It's a dead heat! Who's got the split times? ;o))

Perhaps we should ask Mike to show the posting time to the tenth of a second?

Okay, that's sad. I'll get me coat.
Rob Bell

The 'last posts' put tim ahead, but the thread puts Rob ahead...
Will Munns

oh and you missed the
If you chip your car you'll want to put the super stuff in it.

Will
Will Munns


As Will says


"If you chip your car you'll want to put the super stuff in it."

Chipping with an ICON advances the timing so things can get a little lean causing picking at 3.5K revs, The higher octane fuel can help to overcome this. I must admit doesn't seem to make a blind bit of difference to mine though.

Tim

tim woolcott

Thanks all. Bog standard unleaded it is then.
Paul
Paul

Paul

Try Optimax and see what you think.
Blue Pocket Rocket

I have recently started using super unleaded in my VVC. The first time was by accident, having filled up with Super Unleaded I was aware that the car seemed smoother and also more responsive. I filled up with Super Unleaded a few more times after that and got used to the difference. Just to check it out I used ordinary unleaded for a couple of fill ups and then reverted to Super Unleaded. On switching back I could again feel the difference. I don't feel it is psychologigal, I genuinly think that there is an improvement. It is worth giving it a try and see if you can notice the improvement.

By the way it was Esso Super Unleaded, I have not tries Optimax yet.

Pete
Pete Fincher

I started using superunleaded two months ago. On motorway trips I get 10% better fuel economy 35mpg to 39mpg with a heavy right foot.
Praveen

Having done something similar to you guys, Pete, Praveen, when cruising across Europe (where Super Unleaded isn't as expensive as it is here), I can honestly say that I noticed no difference at all between the fuels, so reverted back to the bog standard stuff.

Maybe there is something different about UK superunleaded? Either way, I'm not sure how economy can be improved with the higher octane fuel? Can anyone enlighten me?

Not tried Shell Optimax, so can't comment on it.
Rob Bell

I was surprised myself but my drivings remained consistent when I've used either fuel and when I filled up with the normal stuff it reverted back to its old mpg. Curious.
Praveen

I am with Rob. I do use the Super in Europe where it is cheaper and 98 octane (as opposed to 97) in the UK. The engine does appear to run smoother but I can see no difference in MPG and I do monitor MPG closely when doing long trips in Europe. I also did a test in our 75 with Optimax on a motorway trip London to Scotland and Esso cooking on the way back. Cruise control set to 85 on empty motorways for both journeys - no difference in MPG - well the Esso cooking was slightly better.

Come on folks, if the fuel companies could deliver a 10% MPG gain for a 3% improvement in octane rating for a 7% increase in price, would they not shout it from the roof tops?

Cheers

Patrick
Patrick Beet

A number of months back... possibly last summer I remember reading an article in Autocar where they did a comparison with three cars, a Jag and B*w and a Merc, using normal unleaded and Shell Optimax. They reported that only one showed any performance increase which was negligible but they had before and after pics of the engine, and there was a significant reduction in the carbon deposits around the valve area after the cars had been running on the optimax.
R Baker

As I wrote in a previous thread on this subject...Optimax improved all aspects of my Alfa 156 V6 2.5, compared to Shell "cooking".....But seemed to have NO effect (or even a -ve effect) on my MkIV Golf 1.8 GTi that I had at the same time.....

So...give it a try and see what you think. I'm waiting 'til my TF160 has covered a few more miles (only done just over 5k @ the mo) before I experiment.

SimonKE

This thread was discussed between 28/01/2003 and 01/02/2003

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