The Octane Thread

[Fusionwhite]

I normally run 95 in mine.... a big problem in Sydney as everyone is ditching the 95 in favor of E10. Higher octane fuels do not generally improve preformance however I beleive (feel free to disagree everyone) that the quality control is higher on premium products so I'm less likely to get a tank full of below spec product

E10 is a mix of RON 92 and ethanol alcohol. The blend gives an octane rating of 95 however....

Ethanol burns faster than petrol so you get less klms than straight 95 from a tank.
Ethanol absorbes water so if your local servo doesnt undertake good housekeeping you will end up with water in your tank.

The most important thing is to get your fuel from a republe source... major oil company owned sites are best as they are less likely to add any "fuel extenders", have good housekeeping policies and are more likely to look after you if it goes pear shaped.

By 2012 the government will most likely mandate it's use in all products and we wont have a choice. I think this is already the case in Europe

[Diego]

For what it's worth, since my the last posting in the thread in December of '07, I've continued to run mine on the lowest octane fuel with excellent results. Fuel mileage has even been better, although this could be in part because the engine is still getting less stiff with wear.

I do make it a point, though, to use major brands whose quality control I trust across all grades of fuel.

> "As for the E10, dunno. Do Triumph approve it's use?"

Yes. That's specifically stated in the manual.

Some of the fuel I've used has been E10 with no perceptible difference in performance.

It's not precisely accurate to say ethanol "burns faster," BTW, but it does contain lower energy per unit of volume (not as many carbon bonds per molcule of ethanol as in most of the compounds that make up petrol), so it's reasonable to expect less fuel economy. However, the E10 blend contains so little ethanol that I'm not expecting to see a huge difference in the mileage figure. Once my bike is run in enough for the mileage to stabilize, I'll check it in detail, but I don't expect to see much more than one to 1.5 mile per US gallon difference.

The difference definitely shows up in E85, according to friends whose cages use it--but we won't have to deal with it in our current Triumphs, and probably not future ones any time soon.

[CrazyCam]

In amongst lots of good stuff, Diego said, of using E10:

"Yes. That's specifically stated in the manual."

I've double checked on Page 42 of my manual, and don't see any reference to E10. What am I missing?

I'd expect it not to be a problem, but I'm a wee bit nervous of that kind of thing since, years ago, I dumped some left over race fuel into a road bike, and the alcohol ate the seals in the fuel tap, leaving me riding in heavy traffic, with petrol p****g all over my leg.... not a fun experience.

[Diego]

I've double checked on Page 42 of my manual, and don't see any reference to E10. What am I missing?

Australian manuals are organized differently from ours, apparently. In ours, the fuel requirements are on Page 44. Under the heading Oxygenated Gasoline, fuels containing up to 10% ethanol or up to 15% MTBE are given the OK.

Perhaps Triumph omitted reference to it in yours because they figure Aussies have too many other uses for ethanol than to waste it by mixing it with fuel.

[CrazyCam]

Australian manuals are organized differently from ours, apparently. In ours, the fuel requirements are on Page 44. Under the heading Oxygenated Gasoline, fuels containing up to 10% ethanol or up to 15% MTBE are given the OK.

Thanks for that, John.

In that case, I will, once run in and consumption stabilised, check out E10 over here.

Perhaps Triumph omitted reference to it in yours because they figure Aussies have too many other uses for ethanol than to waste it by mixing it with fuel.

You may have a point there!

[Shakey]

Seems to me the manual recommends mid grade gas. Once they change off the winter mixtures I'll run 89 octane and see how it goes. I doubt I'd ever run 87 octane. My Bonneville America didn't like the stuff and my Moto Guzzi dislikes it as well. Both run fine on mid grade so I imagine the Street will as well.

[Diego]

What gives you that impression, Shakey? The number in the manual is very clearly 87 (US rating method) for the Street. I've been running it down in Georgia with the warmer weather that's already arrived there (I'm elsewhere at the moment), with absolutely splendid results!

I agree that the Bonnevilles need mid-range gas, except maybe in the very coldest months, but this is not the same engine... not by a long shot.

[CrazyCam]

Well, FWIW, I have been keeping a spreadsheet of fuel used/distance covered for my Striple since I got it.

In this, and other threads, I have said that my previous 600 Hornet would actually go further on a tank of fuel if Premium, 98 octane, was used.

I can now be fairly positive that this is not true for the Striple.

There was no appreciable difference in fuel consumption, from 91 octane ULP, to 98 octane Premium. (Caltex Vortex 98) Nor was there any other noticeable change in performance.

I would expect this to be true for all of the east coast of Australia, as for other places, dunno.... probably.

[tuanmtv]

One articles on "bike" magazine suggested the type of gas for ST is Ron95. Here in Vietnam we only have a type of A92 or A95 gas, I don't know if it is OK to use on the ST?

[Diego]

I have been researching international octane ratings online this evening with mixed results, but it does appear that Vietnam's rating system is based on the RON method. If that is actually the case, the A92 gasoline should work well in the Street Triple.