A cure for the Super-unleaded Problem !!

[HIGHLANDER]

As Superunleaded is becoming more difficult to find in the UK my recommendation is :- 1. Use Superunleaded where available 2. Buy Millers Octane Plus additive and add to normal unleaded. This boosts octane by around two points so will take 95 RON to 97 RON (current rating for Superunleaded, used to be 98 RON as recommended by TVR) Costs about £3.00 for a bottle which does 50 litres i.e. a tankfull. As Super is approx. 7p/litre more expensive than Unleaded it even works out slightly cheaper ! 3. If you are experiencing ''pinking'' problems on Super try adding octane booster to increase to 99 RON. 4. Millers have tested product with all brands of petrol and recommend using Shell fuels for best results. Hope some TVR owners find this info. of use - seems very handy for top ups where S/Ul N/A in the UK or in Italy where no service stations stock higher grade fuel.

[Driller]

thanks Highlander, i was just about to post asking about additives since my griffs been pinking again! Driller Ice Blue Griff500

[Dave_H]

Cheers Highlander, I've been after this sort of feedback for a while now, as my MGBs 1950cc stage3 engine was built in 1997 when 98 ron was available, it's never been the same since that grade has been withdrawn, dispite many different tuning gurus. I'll give that a try.

[Driller]

where can you get the stuff Highlander? I tried Halfords but no luck... Driller Ice Blue Griff500

[fish]

The newly released Shell Optimax brand is now back to 98 RON. Shame it's not 99RON as this brand is on the continent.

[gervaised]

does anyone know if the RON values in america are different to the ones in europe?

[leatheradams]

I was in America a few months ago and I remember their fuel being very low! about 89 and 91 RON! That probably why it's so cheap?

[apache]

can recommend the optimax stuff...Griff loves it

[ATG]

Its so cheap coz they pay vastly less duty than we do. But they also don't have a health service to scrape you off the tarmac. Believe me, if you've ever had any contact with American health care provision, you'll see the benefit of the NHS, decrepid and demoralised as it is.

[gervaised]

quote:does anyone know if the RON values in america are different to the ones in europe?

anyone know?

[trefor]

Yes they are - I don't know the specifics, you get something like 89 or 91/2 RON over there which are the equivalents of our 95/98 octane/ron/whatever. I'm sure someone on this site knows a lot more than that though ... Their gallons are smaller too (3.x litres I think).

[JonRB]

As usual, the americans have to be different. Different gallons and different RON / octane. Different English too, but let's not get started on that. Their ordinary unleaded and ours, and their super and ours, are roughly equivalent, apparantly.

[louise]

Shell Optimax, 79.9p The guy behind the glass did not know the RON, But told me it would make my Griff faster and was better for over taking. YES VERY INFORMATIVE

[Stu H]

OK folks here's the low-down (as far as i know) 1 U.S. gallon = 3.785 litres 1 U.K. gallon = 4.54 litres UK vs US gallon i.e. I UK gallon is 20% larger than a US gallon. OCTANE RATING OF U.S fuel USA Octane ratings are NOT the same as UK octane ratings. i.e. 95RON in the U.S. is not the same as 95RON over here in the UK. 95RON U.S. fuel equates to a HIGHER octane RON rating in the UK. Read this link for more info : http://www.btinternet.com/~madmole/Reference/RONMONPON.html SHELL OPTIMAX Shell Optimax petrol is nominally rated at 98.6RON, which is a substantial improvement on the 97RON that all other Super Unleaded appears to be rated at. MILLERS OCTANE BOOSTER This is quoted as raising 50litres of petrol's octane rating by (quote) "up to 2RON". After several discussions over the past few months with some very experienced tuners and mechanics of very high performance road-cars, about 1RON or so would be a more realistic estimate. but it DOES work believe me. I use a bottle per tankful all the time as extra "insurance" against detonation. It is particularly a good idea on track days etc. Therefore using Shell Optimax and 1 bottle of Millers Octane Booster would result in fuel of approx 99.5 - 100RON. This is of great use in an engine which has a knock sensor and an ECU that detects knock and adjusts the ignition timing as a result of what it finds. An ECU like this will have a "default" ignition timing and will steadily increase the ignition timing until it detects knock (within the parameters tha it is programmed to) and hence will maximise the octane rating of the fuel supplied without advancing the ignition so far that fuel detonation occurs. ---- regds Stu

[marlboro]

Anyone after more info on Shell's Optimax look here: http://www.shell.com They claim a RON of 98+. There's also a list of service stations where its available. Can't wait to empty my tank of BP stuff and give it a try.

[fish]

Just put about my third tank of optimax through the Tuscan, it does seem to go better than normal 95 RON. Maybe I'll start paying more for my fuel and put it in all the time not just for trackdays.