BP Ultimate?

Originally Posted by rowdy

Read an article in a car mag once, they tested shell optimax, tesco 99ron, and bp ultimate. the car they used was an astra vxr, the tesco gave biggest gain narrowly from shell and the bp fuel actually decreased power slightly (bp claimed a dodgy batch of sample petrol). From what I can remember the tesco and shell gave the car an extra 10bhp (approx). The article also stated that the engine ecu takes about 60 miles for it to register the different fuel octane, so if bikes react in a similar way it is possible that you felt some gain,although maybe not straight away.

Is there a single bike on the market with a 'knock sensor'?!?!?

[rowdy]

Originally Posted by Blue_SV650S

Is there a single bike on the market with a 'knock sensor'?!?!?

Don't know, read post #4 ?

Originally Posted by Blue_SV650S

Does your Audi have a knock sensor? ...

As for your pocket, is/was the Super unleaded <9% more expensive?

Audi does have a knock sensor. The S UL was 1.16 / litre, over std UL which was 1.06 / litre. It makes the cost per mile virtually the same. Nevertheless, the mileage did improve.

Originally Posted by Biker_Billy

Audi does have a knock sensor. The S UL was 1.16 / litre, over std UL which was 1.06 / litre. It makes the cost per mile virtually the same. Nevertheless, the mileage did improve.

In that case I am not surprised there was a performance/MPG difference!

Originally Posted by Blue_SV650S

In that case I am not surprised there was a performance/MPG difference!

No performance difference, only MPG. Interesting that the additional cost balances any MPG difference tho - not really much incentive to use it, unless it is that much better for engines, which I doubt.

Originally Posted by Biker_Billy

No performance difference, only MPG. Interesting that the additional cost balances any MPG difference tho - not really much incentive to use it, unless it is that much better for engines, which I doubt.

Just to be a stickler ... better MPG IS a measure of performance improvement ...

Anyhoo, yes, seems it makes no real difference to your pocket, even if you have a vehicle that can adapt to use it proeperly ... I do think the detergents are supposed to be a bit better mind ... but to be honest, when is the last time you heard of modern fuel (normal UL) clogging/coking/gumming an engine!!?!?

Lol, my apologies - I was trying to separate performance (in terms of engine responsiveness, acceleration etc) and fuel economy.

But of course, you are quite right.

Besides, I do the journey for work, So it doesn't make much difference to my pocket

Blue me ol' mucker...I thought some BMW bikes have knock sensors these days...

All else is as already mentioned...no knock sensor, no real improvement. It might help your engine by 'cleaning' but I don't know tbh...

[yorkie_chris]

Originally Posted by zsv650

is it a higher octane thats probably what does it though i dont know didnt really do much for the curvy sv havnt tried it in the pointy though a rr's a different beast altogether.

No it isn't. It's the density of the fuel in a non-knock sensor engine. Closed loop control means that it can get the proper lambda reading (proportional to mixture), by injecting less fuel.

On a turbo engine, or to a minor extent an NA engine, when equipped with a knock sensor the engine can use a little more boost, a little more ignition advance, or a slightly leaner mixture. Better power + more mpg. The power is only majorly increased on a turbo'd motor. NA motor you'd have to increase compression to get benefit.

As to the RR being a different beast, I'm not sure. Does it have a lambda sensor?

My 125YBR used to get 20+mpg more with optimax.

Ragging the crap out of it I could get it down to 70mpg on normal UL, could never get worse than 90mpg with the better stuff.