99 RON super unleaded

[Rockettvr]

Hi All
After a chat with Chris (Jack Valliant) a few weeks back I've started using tesco's 99 Ron unleaded. Now i think i've noticed a small but significant difference in running and performance (the wedge just seems to run a little smoother) but i'm not sure if its real or just my imagination telling me it should be better because of the fuel So quick question - who uses the high octane "super unleaded" fuel and have you noticed a difference in running or performance? Thanks Ron

[V8 Fettler]

Rockettvr said:

Hi All
After a chat with Chris (Jack Valliant) a few weeks back I've started using tesco's 99 Ron unleaded. Now i think i've noticed a small but significant difference in running and performance (the wedge just seems to run a little smoother) but i'm not sure if its real or just my imagination telling me it should be better because of the fuel So quick question - who uses the high octane "super unleaded" fuel and have you noticed a difference in running or performance? Thanks Ron

Reduced detonation in hot weather at high rpm with high loadings. Cold weather = no difference.

[adam quantrill]

If you run it all the time why not tweak the ignition timins slightly to take advantage of it - you'll get a little more power.

I used to run it ages ago but have no Tesco's nearby. Then I discovered you can run 1/2 and 1/2 normal/super and it's just as good. I thing Leigh told me - they used it in the TVRCC racing.

[jmorgan]

95 here. Told I would need a very accurate stop watch to tell the difference.

[marcus1875]

I mix as well. Tescos. Agree that a good stop watch would be needed"

[mrzigazaga]

I use 97-V-power..Only because of the blower...I did have to use 95 a while back and the car ran like shyte!..So anything on or above 97RON Ron..(Sorry mate couldnt resist it).....Ziga


PS: Chris has shares in tesco fuels and ian owns their car park's, Im buying up all their dodgy wheeled trolleys on behalf of an insurance company, We're gonna make millions...

Edited by mrzigazaga on Tuesday 3rd September 22:30

[QBee]

Recently changed my 4litre RV8 engine to a V8D 5 litre. Compression ratio 10:1.
Rob told me to run it on 95 on the road, 97/99 on the track.

Started off with 95, felt ok.
Put some 99 in for a track day and noticed immediately how much smoother, more responsive and eager the engine seemed.
Never gone back to the cooking stuff. Car runs a treat. Had it mapped on 99.

Never shown it a stopwatch.

[Alexdaredevils]

Oh.... One of these threads again

[adam quantrill]

The old ones are the best!

As I can't usually get 99 RON I use Castrol Valvemaster Plus octane boost, for the SX, but I think it may leave crud in the cylinder heads, so maybe not such a good ideal long term.

[matt-man]

I only use super in both my classics....The wedge pinks on 95.

I try and use bp as apparently it doesn't have ethanol in....if people really want scaring, read / research this....this is real and is happening!

http://www.telegraph.co.uk/motoring/classiccars/91...

[mrzigazaga]

Good point about ethanol, Makes me wonder if its a government conspiracy to elliminate classic cars and bikes..After all they dont conform to their expectations..The amount of upstarts that cover their ears when i go past make me laugh..Yeah lets all be sheep and live in a fluffy world of NO noise..NO say..NO soul and NO life...I say.."NO"

[Wedg1e]

I use cooking (i.e. Tesco) 95RON in the 390SE and still get 250bhp out of it

On the Continent a lot of filling stations already have duplicate UL pumps with E5 or E10 Ethanol - the E10 is cheaper.
Essentially the oil companies are swindling us maximising profits by diluting the fuel we think we're buying: while they're throwing Ethanol in petrol they're also throwing vegetable oil in diesel

[RCK974X]

Not directly comparable perhaps but....

Here in new Zealand, the standard unleaded is (supposedly) 95, and the 'Super' is either 98 or 99 depending which supplier.

My 2.8 engine runs OK, but a bit rough on the 95, but runs smoother on the 98.
I can swear I can hear pinking with 95, but whether it's real or not, or just me, I'm not totally sure.

Having fiddled about quite a bit, engine seems to most like 10 degrees BTDC (according to pulley and timing light) and vac advance disconnected, even on the 98 super. This seems to give good economy (27 mpg ish) on a run when set this way, so that will do for me.

Given the 2.8 was designed for leaded gas, the modern unleaded probably burns a bit differently
anyway, even the 98 stuff.


All I can say is to try a few different settings around the 'standard' and see what works best !

Edited by RCK974X on Wednesday 4th September 00:44

[Rockettvr]

Bit if a mixed bag of opinion then. My 350 definitely feels smoother and more responsive on the 99ron although as pointed out probably doesn't alter the performance any great amount. Think I'll gave to do some research regarding ethanol though
Cheers Ron

[PHJayV8]

I always use super unleaded in the M3 and whatever classic car I'm running, it seems to last a bit longer.

Cheap supermarket fuels are false economy IMHO, but will use Tesco Momentum at a push.

[QBee]

I think that's because each car is different. I ran my 4 litre RV8 on 95, 99 made no difference. My 5 litre definitely feels happier on 97/99. So it's the engine, not the driver, that makes the difference. And what you use it for. It's no coincidence that the only fuel sold at Brands Hatch, Snetteron, Cadwell Park etc is super unleaded

[jmorgan]

PHJayV8 said:

Cheap supermarket fuels are false economy IMHO, but will use Tesco Momentum at a push.

False economy? lets see, 18 to the gallon on a good day, do I care.......

[PHJayV8]

jmorgan said:

False economy? lets see, 18 to the gallon on a good day, do I care.......

Of course you do.... Nobody likes paying lotsa pennies on fuel to see it disappearing quicker

[jmorgan]

Work mae asked what the MPG was like, I told him. He said that is not very good is it?........

[QBee]

jmorgan said:

Work mate asked what the MPG was like, I told him. He said that is not very good is it?........

If he wants to bring his Smart Car to Snetterton tomorrow I will happily show him the racing line. He should still get about 25 mpg if he is really trying.......I get 8 mpg in my Chimaera, and proud of it.