Andy4B
Member
Registered: 21st Sep 02
Location: U.K.
User status: Offline
|
Buy a diesel.
|
lacky75
Member
Registered: 8th Dec 02
Location: Norwich
User status: Offline
|
the only diesels worth buying are volkswagon. 
|
Miner
Member
Registered: 28th Aug 02
Location: Ayrshire,Drives: Corsa 12v & CBR600Sport
User status: Offline
|
Optimax burns smoother cos it has a higher level of octane molecules in it (c8h18) which make up the majority of the fuel blend & because it contains more of the optimum molecule it burns smoother & more consitantly. Does work, my car sounds & drives a lot better with it but not enuf as justify the extra cash! esp for the milkfloat! 
|
Cybermonkey
Member
Registered: 22nd Sep 02
Location: Sydney, Australia
User status: Offline
|
Its all about the timing you lot! Octane ratings are not about strength, they are all to do with correct detonation timing inside the cylinders. Optimax has a higher RON (Research Octane Number) because it contains more parts of octane molecules per CCM, as miner says. As the engine timing is different, the engine is responding diferently, creating a more efficient environment for the fuel to burn. Hence the increased MPG and price tag for the extra cost of development of the petrol. Also various additives in the fuel help a little towards increased 'productivity'.
Dave
|
Andy
Member
Registered: 28th Dec 99
Location: Cumbria, UK
User status: Offline
|
Dave is right - ideally, to get max efficiency and power out of an engine, you would have a very high compression ratio. The problem is that once the compression ratio goes too high in a petrol engine, the flame front that pushes the piston down the cylinder doesn't burn smoothly. Instead there an explosion initiated by free radicals>The nergy is released too quickly and can't be harvested - it also is likely to damage the pistons/valve etc. A higher octane petrol basically allows you to get more compression before detonation occurs.
One more thing, Optimax has an average RON rating of 98.6. SUL is around 97
|
