Unleaded or super unleaded?

So you could technically remap it for super and get another pony or two. Another thing to waste my money on. Excellent.

Originally Posted by glade

AS PP said, higher octane fuel is more resistant to detonation (knocking)

Sorry but couldn't resist, you mean pre-detonation after all it better detonate

I just use normal unleaded anyway, never heard a knock yet and just want to pay the gov less anyway

Originally Posted by sideshow46

93???? Thats low. we get 95 as standard, 97 optional at most petrol stations and 99-102 at a selected few.

BTW I use 97.

I'm not sure about the differences in our fuel, but all sports cars and sport bikes run on 93 over here. 87 is standard 89 is midgrade and there is sometimes 91. All the little ricer kids call anything over 97 race fuel.

I put it in on trackdays but don't really feel the difference. I might also use it after winter.

I think I've read that race fuel is 100 octane. Where do you get 102?

P.S. That is a scary pic Hovis. Maybe put the bread avatar back? He he he.

It makes no real difference on the SV... I did some testing a while back and found this...

Averages:
BP Ultimate (97 ron):
Mpg 51.46 KM per Litre:18.21 Pence per mile:8.61 £11.87 137.7 miles
Shell Optimax (97 ron):
Mpg 52.87 KM per Litre:18.11 Pence per mile:8.27 £11.75 142.2 miles
Sainsbury's Super Unleaded (97 ron):
Mpg 51.56 KM per Litre:18.25 Pence per mile:8.12 £11.61 139.5 miles
Sainsbury's Unleaded (95 ron):
Mpg 50.37 KM per Litre:17.83 Pence per mile:8.24 £10.88 132 miles

The only time you will need it is on a bike like the BMW K12.

There is more about it on my blog if your interested.

I do notice a difference in the 'Blade - but whether it's real or imagined I don't know.
The bike just seems somewhat smoother on Super that regular unleaded - most noticably when in town pootling, other than that I get a better mpg...

... though whether that offsets the higher cost I can't actually be arsed to work out. I do so few miles really that it makes no odds.

[northwind]

One of the bike mags did some pretty thorough dyno controlled testing with 2 bikes a while back, and did see an improvement in mpg and a fractional increase in power with the supers over the regulars- but it was a lower percentage than the price difference.

I use regular... Used to use super, because it gave me a warm "looking after the bike" glow. Even with the advanced ignition there's no need for the higher octane fuel, and if my research is right even if I do the busa mod and bump the compression up, I'm still not likely to need super (I'd bin the advancer if I do this)

Originally Posted by R20MAD

The higher octane gives a stronger explosion resulting in higher compression and therefore more power. The trick for grey import cars is to buy a Fuelcat (which adds lead to raise the octane) and run on standard fuel with the benefit of added performance. No reason why you can't fit on to a bike. That and super unleaded would result in around 100 octane!

Not quite correct but almost. Higher octain makes the fuel burn more evenly, sometime if the octain is too low for the compression of your engine you can get it firing before the spark flashes, this is bad as you can imagine, burn out valves and other nasty things can happen .

So the higher the compression the better burning the fuel needs to be hence race engine with massive compression (and high pressure turbo) need the higher octain fuel.

Basically it burns when its supposed to...

Can o' worms time!

[Sid Squid]

Originally Posted by sideshow46

93???? Thats low. we get 95 as standard, 97 optional at most petrol stations and 99-102 at a selected few.

BTW I use 97.

It's different in the States, the numbers are RON, (Research Octane Number), here, and MON, (Motor Octane Number), over there. From memory there's about 7-10 difference in the numbers for the same fuel measured under the differing standards

The most significant difference isn't the power they give, the octane number describes the resistance to 'knock'.

The SV doesn't need any better than ordinary unleaded, the comments about additives stand but there's much disagreement about how useful they are for any given vehicle.