Shell Optimax

[Jock Guzzi]

I use Optimax in my Ballabio but the dealer who sold me my Triumph advised that I just use the standard stuff in it.

 

Am I wasting money using Optimax in a Guzzi. Should I just use the standard stuff (though I would not buy a supermarket own brand petrol).

 

Thoughts appreciated.

[Guest ratchethack]

Jock, the net of this consideration boils down to using the cheapest gas you can get away with without pinging. There will be variations on this depending on lots of things. But most of us - including me - have to use the highest octane gas we can get ahold of in our V11s, and even then, pinging is common on hot days, even with very good PC III maps. If it doesn't ping at all, you might even try a half-tank of lower octane gas to check it out. If it pings, top-off with the good stuff and see how it goes half & half.

 

I would under NO conditions advise loading the engine for any length of time while it is pinging! This will hole the pistons in fairly short order.

[Murray]

Admitted we don't pay anthing per litrte like you do in the Scotland/UK. I run my 1100 sport on the BP equvalent with no problems. It seems to go further to the tank but that might be wishful thinking. The real test is when we pull the motor down (which is possible not hat far away) as the BP stuff has all sorts of wonderful claims like de coking motor preventing build up etc etc.

[Guest Nogbad]

Jock,

 

I was only using Optimax in my V11, and it seemed to give me better mileage and much less pinging than standard unleaded.

 

Some supermarket petrol is ok. The Tesco 99 octane is the highest octane available in the UK and is a bioethanol blend. My Buell runs noticeably better on this than anything else probably because it is mapped for oxygenated (i.e. ethanol blended) fuel. The manual recommends using it as the first choice. It also works ok in the V11.

 

I have done Hatchet's experiment with the blending of standard / high octane, and really, with the price only a few pence a litre different it doesn't seem worth the bother.

[mike wilson]

Paradoxically, older engine designs often need better fuels than newer ones, for the simple reason that the older ones were designed when there were "better" fuels available. 100octane fuel was easily available in the UK until the early 1980s. It had huge amounts of TEL (lead) in it. Just right for your LM I, etc.

 

What I do find with the more exotic blends of fuel is that the insides of the engine are appreciably cleaner than before. After using the "special" Shell fuel available in the mid80s (withdrawn due to problems with Police patrol vehicles, allegedly) I was astonished at how clean my twostroke cylinder head was. Looked just like a four stroke that had been started and run for ten minutes or so. There was a tide mark in the float bowl - below the fuel line looked like as-cast metal.

 

m

 

BTW, anyone tried the BP fuel that's about £2:30/litre? Only available in Essex.....