Fuel additives

[david.hunter]

Having checked out the option of a e10 conversion kit for my 1989 Porsche 911 3.2 Carrera Targa Sport - it looks like the concensus is “don’t go down that rocky road”.
So should I be using a Fuel Additive to my E5 petrol and if so, which is the go to brand?
Valve Master Plus seems to feature in a lot of YouTube blogs but that may be driven by advertising revenue.
Would appreciate your thoughts and experience.
David

 

[911hillclimber]

All additives are driven by profit.

I have run my 1985 3.2 140K engine on 99 octane since I fitted it in 1994.
I drove the car to hillclimb events, competed as hard as I could and drove home for 14 years, then 'retired' the car to less miles and no competition runs.

It runs poorly (but will get you home) on E10.

Today, all fuels carry ethanol, just E5 is UPTO 5%, E10 is from 5% to 10%. The two fuels are mixable.

About 14 years ago I had a Subaru Impreza to road/hillclimb and tuned that to a dizzy 363 bhp at 7800 rpm.
The car was mapped to a mm or less on Shell 99 octane, ehanol free at that time (maybe).

The expert who mapped it insisted on adding an octane 'boost' to each tank full.
The purpose of this was not to increase the octane but to ensure it was 99 octane and stable, ie a known fuel quality.

I did as I was told, and the car was fabulous, never missed a beat for 4 years being thrashed on the hills.
The additive was really expensive, not sure about today.
I imagine E10 and an additive could be as expensive/ litre as E5?

I'm really saying if you use good forecourt fuels around 97/99 octane and drive on the road additives give you little imho.
Run the car on a track, and an octane boost may be a good idea.

Ethanol will damage your flexible pipes quickly.
An additive that removes ethanol may be good.