I have just filled up with Sainsbury’s SUPER unleaded for 93.9 per litre. That seemed quite “cheap” to me. Does anyone else use this brew?
Not used it J but that’s a good price, most Super unleaded where I lve runs at about 95 to 97p a litre.
I read elsewhere on here that a lot of folks say there’s no point in paying the extra as it makes no difference to the performance but I’ve also read elsewhere with our engines its best to use the higher octane rating so I dont know. I do know depending on where I go I can fill up at certain places and get pinking with normal unleaded so I tend to use the Super now all the time and never have a problem.
Personal choice I guess.
Hedge, don’t run your car on 95 octane, you will get detonation with an SC fitted
For a non FI car super is a waste of money
As Geoff says, you need to be putting the higher octane fuel in a forced induction car. For normally aspirated engines, ordinary unleaded is all that is required. Detonation of a sustained nature is bad news!
Hi Geoff/Joanne,
I’m confusticated now! If using Super on a NFI car is a waste of money then who is supposed to use it? My car IS forced induction, isnt it??? And what do you mean by ‘detonation’??? Whatever it is I dont like the sound of it!!!
Hedge
93.9p for super unleaded??? my local morrisons is charging 94.9p for normal unleaded…
Your car is supercharged (forced induction), therefore you need higher octane fuel such as V Power or the Super Unleaded sold by the likes of Tescos and Sainsburys. If your car wasn’t supercharged or turbocharged i.e. normally aspirated, you only need regular unleaded fuel.
If you put higher octane fuel in a normally aspirated car, you are just wasting your money. The engine wasn’t designed to run on high octane fuel and you might as well set fire to £5 notes. The only exceptions would be if your motor was highly modified or you had some clever engine management that was able to sense the higher octane rating of the fuel and alter its maps to benefit from it.
Detonation is when combustion occurs when it is not meant to and you might hear a sound like marbles being shaken in a tin in extreme cases. I believe the real problem is that detonation can be occuring and you aren’t hearing it!
I always use this site to find the cheapest fuel in the area:-
It is amazing how much money you can save by doing a little research!
Strange how supermarkets just a few miles apart can charge different prices. Basically, they charge what they can get away with.
Detonation, caused by a timing/fueling issue and low octane petrol. Broadly speaking the main diference between normal and super grade fuels is the anti knock capability. On a FI[forced induction ] car the timing and fuel mixture are/should be altered as the boost and load change. This always pushes the timing into an area where detonation occurs. The really worrying thing is that it can happen at a noise level that can only be picked up with a knock detector or a stethoscope. Here’s a really good article on the topic
A-HA! Ok, cheers, luckily I use the Super Unleaded all the time. Phew! [Y]
I hate to disagree with a fellow Aussie but I am afraid I find that my 1.6 Mk 1 runs better on 95 RON petrol. It is noticeable and why my original handbook recommends it.
It is reassuring to see how much less our petrol costs (93 pence is about 1.89 AUD).
Martin153
In the good old days, high octane fuels had anti knock agents in them.
But today some of the high octane fuel also have cylinder/piston ring lubricators and advanced cleaning properties to help reduce carbon deposits. I use BP ultimate or Shell V-power, these fuels also burn more evenly producing higher power and reduce pollutants, so well worth putting in your tank whether it is FI or not.
It was well published a short while back that some super market fuels were a bit short on additives causing damage to several engines, so I tend to stick with the big names.
the other Mozza
Got a link to back that up? Don’t mean to sound combative, but there tends to be a lot more anecdote than actual evidence on this topic. My recollection is that “Which” tested super unleaded brands last year, and they rather liked Tesco 99 RON. I’ll try to find a link to that, if you like.
Here is an in depth explanation for detonation and Pre-ignition for those that wish to understand better
Also has some suggestions to cure it
Hi Martin,
Found this,
http://www.bmwcarclubforum.co.uk/forum/forum_posts.asp?TID=41
It did mainly effect BMWs
the other Mozza
I`ve used BP Ultimate or Shell V-Power whenever possible in my Merlot since reading an “Honest John” report in the Motoring section of the Daily Telegraph Saturday edition and Ido seem to get better MPG
Mozza - thanks for looking up those links but, to be fair, neither of them is a case of supermarket fuel being “short on additives”.
The first example is of damage to an alloy BMW used for piston liners in some of their 1990s V8s, caused by high sulphur content in petrol. It only mentions supermarket fuel in passing as the initial suspect before saying all brands were affected, and of course high-sulphur petrol is no longer sold in the UK.
The other example is a case of a bad batch of fuel, contaminated with silicon at the refinery. It just happened to be fuel which was supplied to Morrissons and Tescos.
Stevieboy - do you have any before and after data on your mpg? Over the years I’ve tried my (Mk.1) car on multiple tankfuls of different brands and different octane ratings. None of them made any measurable difference to my mpg.