Hi guys, sorry if this has already been asked-I've had a search but can only find posts about this foreign stuff called 'gas' and octane levels!?

I'm wondering what Petrol the UK guys fill their Bonnys up on, whether it's regular or premium (and is this to do with the octane level)?

the Octane level Triumph recommends is supposed to be about 95 or 94

If you put in lower you may hurt your engine at sustained high speed, above that rating you may hurt your wallet for no benefit whatsoever.

You have to find out what Octane rating your petrol company of choice calls normal or premium, each company differs

__________________
Thai me kangaroo down sport!

I have a 2004 Speedmaster and had the same question 2 years ago. You can run regular gas. You don't need premium, it is a waste of money, mainly because your compression ratio is like 8.5 to 1, but check your owners manual to make sure, 'cause I don't think you indicated what Triumph you are riding.

__________________
"The most happy marriage I can picture or imagine to myself would be the union of a deaf man to a knock out blind woman who digs motorcycles."

Originally Posted by TOMKRILL

I have a 2004 Speedmaster and had the same question 2 years ago. You can run regular gas. You don't need premium, it is a waste of money, mainly because your compression ratio is like 8.5 to 1, but check your owners manual to make sure, 'cause I don't think you indicated what Triumph you are riding.

The 2007 Speedmaster (865cc engine) owner manual states that it is designed to run on unleaded gasoline with an octane rating of 89 or higher. In most areas of North America, 89 gasoline is mid-grade.

It helps keep the thing cooler, and for the difference in cost the cooler running is a good thing. the 790 compression stock is about 9.2 old rule of thumb that would ask for 92 octane, mine is at 10.1 and it runs 92 or 93.5 nicely. it balks a little on 89. another thing to think about is that the premium pump gas is usually just a little older(not so good) but is delivered less often and seems to be cleaner, the sitting around lets the crap settle out ( and that is really good).
look for 100% gas if you can find it, the mtbe and alcohol is hard on the rubber in the fuel sys.

never buy gas if you see the truck filing the main tank, you should see what gets stirred up from the top And bottom of the tank. (not many places filter the gas before it hits your tank, Exon, Sunoco usually does though, this does not help with the water getting stirred in just after their tank gets filled though)

__________________
"Peter, It seems like you have been missing a lot of work recently, well Bob I wouldn't say that I've been missing it"
ENOUGH, go out and ride!

Generaly here in the UK std unleaded is 95 Octane and Premium is 97, I run my 04 790 on std 95 and it runs well, however it is now a 904, just fired it up last night for the first time, Im sure it sounds louder, so will see how it is on std, at £1.10 a litre for std I hpe I dont have to run it on premium
Chris

__________________

04 Bonnie SE. Mototwin silencers, K&N, Slides drilled, Dynajet needles & jets, AI & Snorkle removed, 19T, Wiseco 904 kit, Koni shocks, Lucas tail light & Indicators
http://www.youtube.com/watch?v=OUFeXIAyvHE

Locally I have a choice of 91, 95 and 98 -and I have experimented with all three out of curiosity.

I find the 91 gives a flat spot on accelaration. Cruise speed is no problems though.

The 95 is OK for urgency and feel of the bike.

The 98 makes the bike feel buzzy and I get more vibration through the handgrips - I think due to out of balance forces caused by some pre-ignition. Performance is good though.

I have monitored fuel economy - but what the heck -the difference is less than the price of a cup of coffee between them. I've concluded I would need to lose weight and moderate my riding style before taking this on as an issue.

So now I have settled on 95 for the feel and performance of the bike.

My tuned engine has a compression ratio of about 10.8 to 1. I only use premium/super inleaded, generally Shell or BP.

With a stock engine, there is no point IMO.

__________________
Rob
http://www.triumphrat.net/memberalbu...ry.php?cat=524
http://www.triumphrat.net/memberalbu...ry.php?cat=529

keep in mind that different countries' octane ratings will be different. Here in the US we use the (R+N)/2 rating. I think other places might use only the R or N method, or perhaps something else? With my stock compression I run 89 in the winter and 91 in the summer just in case (the summer is brutally hot here). At 115 degrees F getting stuck in traffic and heating up, then having an uphill climb or something I'd worry about low octane.

__________________
Mr. Whatisit? That guy treats objects like women, man.

Originally Posted by uzidzit

just run the highest you find around... It helps keep the thing cooler, and for the difference in cost the cooler running is a good thing.

That actually is not true, the octane rating of the gasoline you run has no bearing on the operating temperature of the engine.