I ran my RS Turbo on Tesco unleaded for about 2 years until I started modifying it then I switched to Esso Super Unleaded which is what it runs today. The Tesco 99 ron fuel is ok in it, but the BP Ultimate makes it run shit. My Fiesta runabout get's tesco's finest 95 ron unleaded

 

If hypothetically you ran a car mapped for 95RON fuel on a 109RON race fuel, under hard load (full boost, 5th gear, sustained period of time) you could cause damage to the engine as without sufficient ignition advance for that fuel, the exhaust gas temperature would rise, potentially causing the same damage as a lean mixture...

 

the higher octane dosent increase power, it just has a higher resistance to detonation so you can "tune" an engine for more power. Have a read up one what ron/mon/son stands for and how they come up with an octane rating.

 

i found a old graham bell tuning book 'modern engine tuning' on the scribd.com which had good bit of info in it about fuels but cant seem to find it theres an even older one one there from 1972ish but i dont think that one had anything about fuel. Ill see if i can upload it later the more recent one later.

Edit: http://rapidshare.com/files/30020014...ine-Tuning.pdf chapter 3 is good read if you want to find out a bit more about fuel

 

Only if you were driving a modern car with knock sensors would you be able to feel the effects of higher octane fuel straight away.

 

I mostly use morrisons petrol in my cars too.Ive never had a problem.

 

a lad i work with fiesta broke down.Took it to the ford dealer they took his fuel tank off and it was blocked with a silicon grunge.They asked where he gets his fuel from he said morrisons.The garage got on to them and they paid his bill.Me i only use v power from my local shell station never use supermarket fuel

 

I live near Shell mex fuel refinary (or whatever it's called) and noticed that Jet and Shell tankers both 'fill up' from the same point.

Therefore it has to be the same fuel?

 

i normally use shell vpower or ultimate in my escort rs turbo, never noticed any difference, ive even put 95 ron in and not noticed any difference, i understand that the higher rating ron fuel will be safer for my car but ive recently just filled it up with tesco 99ron, their is a thread i started in escort rs turbo room https://passionford.com/forum/ford-e...co-99-ron.html where i asked about this fuel and courtney motorsport http://www.thorneymotorsport.co.uk/t...s_Update.shtml did a test and tesco 99ron turned out to be a very good fuel.

im going to stick to which ever high rated fuel i can get my hands on in my area, its off for mapping on monday so im going to fill my jerry cans with vpower and put that in the tank when i get there to mix it all up.

 

My mum was told to use supermarket fuel in her car - when she first got it (brand new) she put 97 in and it burned the cat out within a week ! They replaced it all for her though....

 

Indeed, the effects of incorrect fuelling are many and varied!

No, you're entirely missing the point. Higher octane fuels allow more advance/boost and hence more power, otherwise there would be no point in using them. Just because they can make more power ONLY when the engine is mapped for them, doesnt mean they will magically make more power when you put them into an engine mapped for 95. I NEVER said they couldnt make more power, just that they wouldnt without appropriate mapping.

Exactly, at last! You map an engine for an amount of advance and boost at any point that is limited by the fuel you are using. Using a better fuel after the map is complete wont gain you power.

Bollocks. Most modern cars with knock sensing allow the car to retard the ignition from the basemap but not advance it. Hence in the case of the subaru described (which was probably mapped on japanese fuel or at least 98) it would retard the ignition and LOSE pose when run on 95. If however you took a car mapped for 95 ron, it wouldnt advance the ignition to take advantage of the greater det resistance of the 98 ron fuel and so there is no point in using it!

 

So, a week after buying her brand new car, what was it that made her realise her catalytic converter had failed?

 

Why would EGTs rise?

 

Yet another reason why "pushrod on carb" makes life easier.
I guess older cars should run better on 'Super' as 4 star was 98RON and normal unleaded is only 95.

I use any old shit except for stuff from the local Texaco. No performance problems but it drinks it. Sod knows why but I get noticeably less MPG with the stuff.
Bizarrely my old Morris Minor (designed in the times when fuel quality was probably anyones guess) actually went better AND did more MPG with one of these 'Advanced' fuels.
No placebo - I was anal enough to keep receipts, figures, etc. and discuss with the wife.

 

alexf - egts potentially rise because effectively the ignition is now massively retarted.

Dunketh - I dont believe they make things easier at all. Life couldnt be simpler now, but a uk spec car, fill it with 95 and smile, ignore all the fucking bull.

If you buy a JDM car, or have your modified car mapped on another fuel, use that.

 

Are all UK cars mapped to 95ron as standard??

Can using 99ron fuel in a 95ron mapped car ,apart from beign a waste of money, can it be harmful?

 

Can't be bothered reading all the replies - but theres no such thing as "rejected fuel". I have a close family friend who used to (until very recently) negotiate the sale of fuel between Exxonmobil and the likes of Tesco, ASDA etc. The fuel on supermarket forcourts is no different to that of Essos.

The reason suprmarket fuel is often the cheapest is because it is sold to them cheaper than you might imagine - reason being that the likes of Exxonmobil, Shell, BP who are selling the fuel to supermarkets are effectively passing on the risk of customer's not paying for fuel to the retailers.

 

Why?

The ignition will still occur at the same time!?

 

its my undeerstanding that higher octane fuels burn more slowly and hence can be ignited sooner, but also must be ignited sooner to avoid still burning gas being exhausted. you are right that ignition would occur at the same timeand this is the problem.

 

Supermarket fuel is also cheap as they don't need to make as much profit on it as a regular petrol station, in many cases the supermarkets just cover their costs and use the cheapness to lure people into the shop!!

 

lads lads lads,

great topic but loads of opions including myself,where are the facts...

I challenge Performance ford or Fast ford to do a shoot out of fuels on 97 v 99 as most cars here id imagine are mapped to 97 ron.i use pysdo 99 but not for the increased octane but because 97 aint available and im mapped for that.A buddy of mine has 3 drums of e5 fuel and is waiting for the right eng to run it through on the dyno against 97 ron.might put a mag in contact with him if he is agreeable....

 

Pinking is actually the word used to describe the noise you hear when an engine is detting.
Detonation occurs after the spark fires and can be caused by several things:- too much ignition advance, octane rating of fuel too low, too high a compression ratio, too high a booost pressure and high inlet temperatures to name a few. Damage can occur if it isn't stopped and normally results in a partially melted piston or broken ring land.
Pre ignition is where the charge ignites before the spark. It's normally caused by a localised hot spot causeing the ignition wether carbon, plugs or a sharp edge glowing. It can cause the charge to ignite even before the piston has reached bottom dead centre, damage in the worst case can be almost instant and often the result is a hole in the centre of the piston.

to put detonation another way a rally team i used who map group a cars,group n cars and WRC's said its like a hammer blow on the pistons because the spark ain't right,either you nacker your piston or top end or the hammer blow effect nackers your bottom end.
with me cozzie its superchipped (not this remapped bollocks) and its chipped to run super,with me evo its a jdm and runs higher octane fuel from japan std. i got told to run it on optimax or 99 which i do and shuv some octane booster in if i give it some big revs.
cheeRS.

 

Irrelevant round here most of them are the same price with only BP being dearer (about 3-4p per litre) than all the Shell, Jet, Morrisons, Total. Most are close enough to each other to keep prices keen and vary by 1p/ltr.

As said above this thread lacks the facts and a definitive answer. Yes the tankers all get filled at the same refinery but what additives are put in for the "branded" fuels other than the high performance fuels?
How do people explain cars being affected by different fuels, just 95 for the sake of argument. Mine runs totally different on BP as said earlier and yet i've never experienced a problem on Morrisons, Jet or Shell. Even my mondeo was the same it never ran well on BP.

 

As long as you stick to 99ron fuel you should be fine without addatives. Rev's wont damage the engine, as the load will be lower, you'll do more damage if running on the incorrect fuel by "loading it up" i.e. full throttle as you come on boost in the higher gears.

I'm not sure why you think your cossie is better because it was "superchipped" not remapped


Most new Evo's and scoobs have agressive enough map's to warrant using at least 97 ron fuel.

Shells Vpower IIRC is the only fuel made specifically to be a "performance" fuel.

Supermarket fuels aren't rejected fuels they just buy off the bigger oil companies and sometimes sell cheaper.

 

No, it can't, unless the car was mapped for it originally and you have since been testing the power on a lower octane fuel, which is what I said. Try reading the fucking thread.

 

Don't think cars run very well on Newcastle Brown.

 

Havent read the thread, cant be arsed but.

Supermarket fuel is inferior to branded fuel. It all passes the kitemark standards etc but it doesnt have the same blend of additives that the branded ( more expensive ) fuel does.


For those of you questioning that you have seen this tanker and that tanker filling from the same place, thats true, the fuel is all carried around in tankers as a 'base' the additives are added on delivery to the station.

Every car i've ever had has run noticeably shitter on supermarket fuel and done less mpg

 

Its where you add 'powered by fairydust' stickers, pink seat covers and lose all ability to drive.

 

It may take more than a map to release the potential that a higher octane fuel can give

Ideally the engine would be specced for the higher octane fuel to begin with.

Just using higher octane and remapping/advancing the ignition may NOT give any more power necessarily

 

where are the mags

Please end all this I KNOW BETTER THAN YOU

 

What questions do you want answered then guys...

I've done alot of work with Fuels at ford on R&D and have contracts in Castrol I can ask questions to if need be....

Alex

 

My understanding is that is changes way the fuel ignites rather than the way it burns.

A lot of people get the idea that because avation fuel is high octane and burns slowly that ALL high octane fuels do....

Alex

 

but 99% of the time it will....

earlier ignition equals higher cylinder pressures which gives you more torque/power.

But to be fair you could change the compresion ratio to take advantage of higher octane fuels as well.

 

we always recommend branded fuel in newish ford diesels as we have seen to many go down with knackered fuel pumps,injectors etc from using supermarket fuel. a local morrisons is one such well known culprit.

my car runs exclusively on shell v power and even my old transit gets shell fuel as its the same price as the supermarkets round here.

 

dunno if any of you lot know this but back in the day a cozzie that was "chipped to fuck" was not necessarily stone chipped.

remapped to fuck doesn't sound as good


regards the old detonation bitd also cosworths ran high octane race fuels containing toluene to combat it.
the fella who told me to run octane booster in std chipped jdm cars when revving the engine hard does the british rally championship and wins rallys so i don't mind taking that kind of advice