GolfGTIforum.co.uk
General => General discussion => Topic started by: Luke1981 on 29 September 2011, 23:03
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Is supermarket fuel actually inferior to other petrol station fuels like shell etc or is it a old wives tale?
Been having a debate at work about it. I thought it all comes from the same refineries!
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All the same.
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All comes from the same refineries. Individual companies buy it then add their own blend of additives then sell it. ESSO and BP I think are the 2 who sell it to Shell, texaco, tesco etc.
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Take a look at this thread, http://www.golfgtiforum.co.uk/index.php?topic=122951.0 (http://www.golfgtiforum.co.uk/index.php?topic=122951.0) was a very detailed with good info from a member who works in the industry.
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Take a look at this thread, http://www.golfgtiforum.co.uk/index.php?topic=122951.0 (http://www.golfgtiforum.co.uk/index.php?topic=122951.0) was a very detailed with good info from a member who works in the industry.
A 19 page thread , you sure :grin:
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Why then do some car manufacturers including VW will state not to use supermarket fuel?
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Why then do some car manufacturers including VW will state not to use supermarket fuel?
Who do you think they develop the car with?
They aren't going to nip down tesco and buy 500 litres of unleaded to test the engines on are they.
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Why then do some car manufacturers including VW will state not to use supermarket fuel?
Who do you think they develop the car with?
They aren't going to nip down tesco and buy 500 litres of unleaded to test the engines on are they.
I would it's cheaper :grin:
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Yup especially when i got 15p a litre off cos we needed Bum roll dishwasher tablets and funnily enough laundry stuff nae bad i suppose only if u need the sh!te like!
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ive always used morrisons as its local and the cheapest near me, only ever had one problem, as old car was running like sh!te, spoke to a mechanic and he said it was just a bad batch of fuel, duno how true this was
ive actually today, just filled a full tank up of shell vpower, as i never have and a few mates have recommended it, cant say i notice a difference just yet, anybody know if its a 97ron or 99ron??
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Why then do some car manufacturers including VW will state not to use supermarket fuel?
Who do you think they develop the car with?
They aren't going to nip down tesco and buy 500 litres of unleaded to test the engines on are they.
I would it's cheaper :grin:
Are there not different "grades" of fuel though?
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I know for a fact the fuel coming into Avonmouth, Bristol get distributed to BP, Shell and Tesco in the south west. All contain the same fuel but you will pay 15-20ppl over Tesco prices at some forecourts.
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All fuels must conform to British Standards. Hence the BS 95 RON on the pump. Petrol is the same but individual retailers may add their own "additives".
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Thanks for the info lads :smiley:
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Why then do some car manufacturers including VW will state not to use supermarket fuel?
Who do you think they develop the car with?
They aren't going to nip down tesco and buy 500 litres of unleaded to test the engines on are they.
I would it's cheaper :grin:
Are there not different "grades" of fuel though?
Yes 95 98 & 100.
Don't believe the hype, additives do not make it a different grade.
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It comes out as 95 through fractional distillation and cracking. Ethanol or Methanol make it stronger normally.
Additives are usually a % of antifreeze, or in diesels case a non emulsifying agent.
Good enough for you?
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FYI Tesco gets its fuel from Greenergy.
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It comes out as 95 through fractional distillation and cracking. Ethanol or Methanol make it stronger normally.
Additives are usually a % of antifreeze, or in diesels case a non emulsifying agent.
Good enough for you?
I wasnt having ago mate, just curious is all :smiley:
So if i put methanol in my tank it would increase the octane?
Yes but its aggressive stuff and can you remember the last time you saw methanol to buy in your local garage. If your engines not optimised well enough or adaptable enough though, theres not much power gain and the economy goes down as there isnt as much energy in alchohols as there is in petroleum, A lot of countries use weak ethanol blends, Thailand, USA etc etc and their cars need to be optimised because of the aggresive nature of the fuel. Wierdly its not as aggressive and doesnt affect rubbers and metals in much higher doses so not such a problem with E85 :undecided:. Guess who's been looking into E20 fuel and its effetts on fuel pumps and rubber hoses all week at work :rolleyes: :laugh:.
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@ wolf boy: Not quite, they are blended together before being sent out.
Methanol is actually quite agressive towards metals. Acetone is blended in as well to help it mix.
Basically, don't do it. You will break stuff. :smiley:
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Not again!!
A Higher octane rating in petrol is a measure of the fuels ability to resist pre-ignition due to compression.
I.e pinking, The fuel partially exploding on the compression stroke before the spark Plug has been able to fire.
An engine can obtain more power from the fuel if it can compress the mixture more before it ignites it.
Hence higher Ron fuels mean the engine can retard the ignition timing and develop more power as a result.
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methanol is funky stuff, needs treating with a lot of respect tho
its really good at poisoning you, as said it will corrode metals esp aluminium, and blending lots of it with petrol and running it in a std car will end in tears, petrol burns with a stoch AFR of 14.7:1 methanol about 6:1 so you end up makeing your engine run lean.
really need a separate tank and 2nd set of injectors just for the neat methanol. also get big problems with alcohol and petrol blends when they get wet, only dry alcohol will mox with petrol if theres any water in there it won't, as for efficency it's not as bad as youd think ethanol contains more energy than methanol ( but methanol is cheep ) but alcohols lend themselves to highe compression ratios so naturaly helps thermal efficency. downside is in winter neat alcohol don't vaporise very well so starting is intresting
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So to summarise this whole debate, Supermarket fuel is not bad, it just has different additives. Higher octane fuel will not make a blind bit of difference to the majority of cars. Highly tuned cars will benefit slightly, higher output cars will only benefit on long runs where fuel economy will be improved, thus making back the slightly extra price you pay at the pumps. But with lower output cars, you will just be throwing money away. 99% of manufactures state to run them on 95 RON anyway.
I think thats the jist of it, no............
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Yeah pretty much, except you'd be surprised how many cars can benefit from higher RON fuels.
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Ssssoooo, from what was said earlier in the thread, do you have to do anything to the fuel system/engine on imported cars to be able to run without complications?
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It would be wise to do a full filter change as generally anything outside of the "better" EU countries have pretty shoddy fuel in comparison.
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Yeah pretty much, except you'd be surprised how many cars can benefit from higher RON fuels.
Indeed. My slightly modified VR6 runs noticeably better on Shell V-Power (99 Ron)
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Pretty much anything with even a rudimentary knock sensing system, even a mk2 digifant has this.