Have been running my Octy vRS on Optimax since new, since it was Revo'd I have also used Millers Octane booster. Decided at the weekend to try some BP Ultimate and Millers Octane booster and the car not only sounds better but seems to run a lot smoother. What are your experiences of Optimax and Ultimate?

Cheers

I had always run on Optimax til a few months ago and then tried Ultimate. Now try and fill it with Ultimate when possible - seem to get about 2-3mpg better

However, there was a test recently where optimax & ultimate were tested against shell & BP normal using a ford focus which had its tank drained between each fill. The result? In terms of both performance and MPG, absolutely nothing. The test did end by saying that both Shell & BP stated that Optimax and BP work better if used regularly s it keeps the engine cleaner

i've noticed i get better mpg with ultimate than anything else any my driving style never changes so its not down to me... i filled with optimax the other week and got 320 out of the full tank, ultimate always gets 330+.

one thing i do know about optimax is it "goes off" after a few days in the tanks at the forecourt so you dont get the full gains from it if it isnt fresh. i dont think ultimate suffers this.

i have heard that octane boosters can damage the exhaust valves though. (referring to daveu's post about cracked valves).

neither its all marketing hype get sainsbury super for 1p more than their normal 95ron and add some aditives of your own.

i've noticed i get better mpg with ultimate than anything else any my driving style never changes so its not down to me... i filled with optimax the other week and got 320 out of the full tank' date=' ultimate always gets 330+.

one thing i do know about optimax is it "goes off" after a few days in the tanks at the forecourt so you dont get the full gains from it if it isnt fresh. i dont think ultimate suffers this.

i have heard that octane boosters can damage the exhaust valves though. (referring to daveu's post about cracked valves).[/quote']

Millers don't mention about it damaging the valves :eek: Have been using it for a few thousand miles now. What sort of Octane Booster damaged the exhaust valves, can't find the post.

I've noticed a couple of your posts stating your regular use of octane booster. Genuine question, why?

"I've noticed a couple of your posts stating your regular use of octane booster. Genuine question, why?"

Well, these octane booster's are there to make the explosion in the chamber bigger to give a greater push down on the piston. But there is one known problem with this is that the bigger explosion the higher the heat level and excess heat on the valves causes them to crack.

Hope this helped

Dr Vrs

Well, these octane booster's are there to make the explosion in the chamber bigger to give a greater push down on the piston. But there is one known problem with this is that the bigger explosion the higher the heat level and excess heat on the valves causes them to crack.

That I understand. I was wondering why you would use them regularly. Track days or RR days fair enough but day to day driving surely you're asking for trouble.

Well' date=' these octane booster's are there to make the explosion in the chamber bigger to give a greater push down on the piston. But there is one known problem with this is that the bigger explosion the higher the heat level and excess heat on the valves causes them to crack.

QUOTE=rich1068']That I understand. I was wondering why you would use them regularly. Track days or RR days fair enough but day to day driving surely you're asking for trouble.

The reason I have been using Millers Octane booster is that my car has been Revo'd and I am running the 98 ron program. As optimax can vary and BP ultimate is 97 ron I thought that by adding an octane booster it would do less harm than using lower octane fuel and guarantee a minimum 98 octane fuel. So by the same principle of an octane booster damaging valves does optimax which is 98 ron damage valves more than a 95 ron fuel :confused:

The reason I have been using Millers Octane booster is that my car has been Revo'd and I am running the 98 ron program. As optimax can vary and BP ultimate is 97 ron I thought that by adding an octane booster it would do less harm than using lower octane fuel and guarantee a minimum 98 octane fuel. So by the same principle of an octane booster damaging valves does optima which is 98 Ron damage valves more than a 95 ron fuel :confused:

I wasn't having a go. Sorry if it sounded like I was.

I understand your logic but I don't know enough about octane boosters. I just imagine that prolonged use of these products would be harmful.

I was just genuinely curious. Any other opinions would be welcome.

Interesting thread, I also use Millers Octane+ at every fillup with Optimax.

This allows me to run slightly higer timing with my SPS3.

Millers state nothing regarding the problems mentioned in this thread and have said that its fine for everyday use.

I wasn't having a go. Sorry if it sounded like I was.

I understand your logic but I don't know enough about octane boosters. I just imagine that prolonged use of these products would be harmful.

I was just genuinely curious. Any other opinions would be welcome.

rich1068

Didn't sound like you were having a go, sorry if it sounded like I had taken offence I too am genuinely interested in this but from what I can gather, using Millers Octane + in the correct dosage, ie 1 bottle every 50 litres of fuel, should have no adverse effect on the car, as it only raises the octane level by up to 2 points.

i would have thought if the car was setup to use higher octane fuel with a remap then running the octane booster shouldnt cause too much damage, it would be advisable to consult the tuner though. running it on lower octane fuel i.e. 95ron wont damage the engine just produce less power.

i would think the remap would add sufficient air to the mixture anyway to cop with the higher levels and reduce the risk of damage.

didnt know the car was remapped.