Shell Optimax - your views?

[mrtristan]

Nonsense. My grandpa used to walk 5 miles in the snow, barefoot...

Seriously, that is a lot to pay for gas, or petrol, as you crazy Brits say. What's the minimum wage over there?

[rallynavvie]

Higher octane fuel has a higher flashpoint. Most cars cannot take advantage of the higher flashpoint and therefor will get worse performance and fuel economy than on lower octane fuel (or whatever it states is the recommended octane in the operator's handbook). Generally engines with higher compression ratios (such as many BMWs and some variable valve timing NA engines), superchargers, or turbochargers require higher octane because the timing requires something that doesn't ignite easier at those compression values. For all practical purposes your car will get more power out of the least octane fuel it can run on without predetonation occuring. Sadly, the "stunnaz" that put 93 RON in their stock mid-90s Cavaliers are not getting more power from it as they say they are

My car stock required 89 RON fuel, which is mid-grade in the US. When the turbocharger was added the fuel requirement went up to 93 RON to take advantage of the pressurized air the turbo was creating. Now that I have a completely programmable ECU in the car I can utilize 93 RON for daily driving, and 104 for when I go to the track. I have fuel and timing maps tuned for both fuels, the one for the track having timing advanced across the spectrum and fuel delivery a little higher at the top. I also run 10psi of boost (~.7 bar) on the 104 rather than my usual 5psi around town so that makes a bit of a difference. When burning off the remaining 104 after filling with 93 and running on the 93 map the engine tends to smell rich because it isn't burning off the remnants of the 104 as thoroughly as the 93. And I don't even want to know what would happen if I ran the 104 map on 92 octane. Something along the lines of a cylinder shooting out the side of my engine bay

[binks120]

and guess who i work for ????BMW LOL

Higher octane fuel has a higher flashpoint. Most cars cannot take advantage of the higher flashpoint and therefor will get worse performance and fuel economy than on lower octane fuel (or whatever it states is the recommended octane in the operator's handbook). Generally engines with higher compression ratios (such as many BMWs and some variable valve timing NA engines), superchargers, or turbochargers require higher octane because the timing requires something that doesn't ignite easier at those compression values. For all practical purposes your car will get more power out of the least octane fuel it can run on without predetonation occuring. Sadly, the "stunnaz" that put 93 RON in their stock mid-90s Cavaliers are not getting more power from it as they say they are

My car stock required 89 RON fuel, which is mid-grade in the US. When the turbocharger was added the fuel requirement went up to 93 RON to take advantage of the pressurized air the turbo was creating. Now that I have a completely programmable ECU in the car I can utilize 93 RON for daily driving, and 104 for when I go to the track. I have fuel and timing maps tuned for both fuels, the one for the track having timing advanced across the spectrum and fuel delivery a little higher at the top. I also run 10psi of boost (~.7 bar) on the 104 rather than my usual 5psi around town so that makes a bit of a difference. When burning off the remaining 104 after filling with 93 and running on the 93 map the engine tends to smell rich because it isn't burning off the remnants of the 104 as thoroughly as the 93. And I don't even want to know what would happen if I ran the 104 map on 92 octane. Something along the lines of a cylinder shooting out the side of my engine bay

[Craig Tucker]

Seriously, that is a lot to pay for gas, or petrol, as you crazy Brits say.

Bit crazier to call a liquid, gas

What's the minimum wage over there?

£4.50 per hour

[flaninacupboard]

did it change this financial year then? thought it was £4.20 for over 18, and £3.70 for under 18?

[Craig Tucker]

I am a bit ahead of myself, it increases to £4.50 per hour in October for those over the age of 22

http://www.dti.gov.uk/er/nmw/

[tgpo]

It changes based on your age?? That sucks!

[mrtristan]

Doh!

Bit crazier to call a liquid, gas