Talk Morgan Forums Community The Malvern Arms High Octane Fuel

At the weekend I missfuelled the Roadster with VaVa Voom fuel.

What a contrast to the cooking grade.

Am sure its not my imagination ...but she really takes off under acceleration.

Anyone else with any experience of this ?

Might missfuel more often now!!

High octane fuel doesn't actually have any more energy content than lower grades, but as it is more resistant to pre-ignition, the knock sensor and ecu will allow more advance resulting in more power. This only works in cars with knock sensors. If a carbed car does not ping on low grade fuel switching to high grade won't improve performance (except for a possible placebo effect).

regards,
Phil

That only works if your ecu always trys to advance the ignition as far as it can before the knock sensor vries enough.

If the roadster ecu is such then yes it will feel faster. If the Roadser ecu only pulls a reasonable and on the safe side ignition advance as tested at the factory then maybe not.

But the Roadster and also my Sigma 4/4 have knock sensors. The power is improved. It works so significant that on some very modern cars, the knock sensor works but will nevertheless not allow the ignition system to go more advanced because some insurance companies were unhappy with the win of power. As far I know, the Ford engines in a Morgan will allow, but I don't know about the P4 GDI.

I use superunleaded in my remapped 4/4 sigma and it certainly makes a difference !!!

I remember VBH doing test runs for Fifth Gear with standard and high octane petrol. If I remember correctly it had no effect on some and limited effect on others.
Marginal bhp increases with some and slightly better throttle response but not enough for most people to really notice.
When I had a Focus TD as a commuter car I used Millers additive. Combined octane booster/cleaner. Over a long period of testing I worked out it gave about 25/30 extra miles per tankfull. I did not really notice any power/throttle response changes to set me whooping!Cost saving was £25 per bottle of Millers . Bottle cost about £11 and extra miles over it's use gave £36 saving ( net £25).
Driving was higher motorway cruising than non motorway. About 2/3 of annual mileage.
I tried it previously on a Renault TD but no improvement /saving to make it worthwhile.
It definitely boils down to the ecu/engine design etc.and the ability of the car to adapt.

Not sure why you would use octane booster in a TD could it have been injector cleaner.

I don't notice any difference either in performance or consumption :-(

I ran a series of Imprezas in the 90's and super unleaded certainly made a difference. After 1000 miles or so they were quicker and smoother. I've
always run my Mogs on V Power where possible so can't comment on any difference so watching this thread with interest.

My M3W runs smoother with 98/100 Octane Petrol as available in Austria. Not really any influence on performance and consumption.