102 RON

[knuckles]

Please excuse me if this has been asked before,is there any benefit or harm in running super unleaded(apart from the damage to my pocket!).Various forums expound various theories,so I will ask the experts!
P.S.I am running a 2002 4.2 SE.

[Martec]

Hi,

We are in the midst of fuel changes again with ethanol being added now, previously it was removal of lead and its replacement with a cocktail of other carcenogenic chemicals.

I have been putting super unleaded in all our old cars for a while now as it was reported that the super unleaded had less ethanol in it, but that will change.

There is a date when vehicles produced from that date have their fuel systems future proofed from ethanol, but I'm not sure when that is. Our 07 focus is run on 95 octane as it is supposedly ok.

The FBHVC have tested products to help reduce the corrosion but as usual time will tell. some say the car runs better on 98 octane, ours don't.

Best of luck

Brian

[J44EAG]

In my experience and humble opinion, super unleaded is a rather more refined and energy packed fuel.

My 4 litre V8 is particularly fuel concious on account of having a modified fuel and ignition remapped ecu. To get the best from the remap, fuel quality and octane rating have a significant effect on the speed of throttle response, power, torque and anti knock control.

On normal unleaded, throttle response can be a tad slow from stand still. Under the same conditions, running on super unleaded certainly gives the car a smarter response and an improvement in smooth running at idle is very noticeable.

On the open road super unleaded response at full throttle is very noticeable. Performance is rather more staid on standard fuel.

I don`t notice much difference in fuel consumption, super compared to standard but do enjoy the super experience more because the car appears to be "content".

As regards what active ingredients are in each type of fuel, others know more about that than I do. Most certainly 98 RON has a higher anti knock rating than 95RON which is good for high performance or remapped/tuned vehicles. Whether 98RON has less ethanol in it I don`t know. That being the case, I often add dry fuel additive to my fuel to chemically mop up destructive moisture content which my be lurking in my fuel tank. Anything I may be able to do to stop corrosion forming within fuel system components I will do. The problem is certainly seemingly more prevalent in a marine environment where corrosion control, tank contamination, micro bacteria and undesirable deposits are a constant and never ending battle. With road going vehicles such issues tend to be easier to control as fresh fuel gets added to a car in normal use on a regular basis.

The worry of course is that high levels of ethanol in fuel can cause detrimental effects on cars stood for long periods or where internal fuel system components were not designed to come into contact with ethanol type fuels. That I suppose is really what the issue is all about. Newer cars it is hoped would be more capable in resisting the effects of ethanol fuels than those of yesteryear.

For preference with a modern V8 jaguar motor, I favour super unleaded. I`d rather pay the extra cost of the fuel if the engine is more lively to use, is sweeter on that fuel and most importantly of all, IF that fuel helps with preventative maintenance and ensures that I am doing what I can to keep that engine alive as long as possible.

Mike

[knuckles]

Thanks for your comprehensive answer,as someone who worked offshore I know the importance of biociding the diesel tanks,thankfully I won't have to do that!As it more likely to do more good than harm I think that I will switch.
Thanks once again,
Frank.