Regular or Premium Petrol

[Joe Newton]

And make you a sexual Tyrannosauraus.

 

 

Tyrannosaurs were only sexually voracious because their little arms couldn't reach their crotches.

[Mark Bolam]

Great film Mick!

I've run my saws on allsorts with no bother.

Maintenance and a spot-on mix is more important IME.

[flatyre]

there are rumours about that the amount of ethanol in regular fuel has doubled and to be honest regular fuel doesn't have that nice petrol whiff that I remember as a kid, plus it doesn't look as clear to me, and if I leave a machine for a lot of months without starting it, it usually requires fresh petrol. I have been using BT ultimate for a few months now but too early to say if it does any better, heard a lot of good things about aspen but never tried it, as pointed out already an accurate fuel/oil mix is very important and draining a machines system of fuel if your not going to use it for a while is good practice.

[Stubby]

Are BP doing phones as well now ?

[GardenKit]

Many people think that Premium (higher octane) petrol has, 1) a higher energy value than Regular and will therefore, 2) produce more power.

 

1) It has not.

2) It can, in the right engine, but will produce less in the wrong one.

 

High octane fuels are in fact just a little 'deader' than regular. This is because higher octane resists detonation for longer and can enable higher compression engine to fully combust their fuel without 'knocking'

 

Use low octane fuel in a high compression engine and it burns very quickly after ignition and develops it max pressure too soon in the cycle resulting in a waste of energy and a 'knocking' or 'pinking' which causes engine damage.

 

A high octane fuel resists the temptation to burn and expand too rapidly, which means the power is released progressively past TDC and downwards on the power stroke giving max efficient energy usage and max power.

 

But high octane fuel in a lower compression engine results in the burn being too slow and energy being wasted towards the end of the power stroke, resulting in loss of power.

 

Standard saws have compression ratios suited to regular fuel, so using premium is counter productive. Only Spuds ported and lowered squish saws may benefit from high octane.

 

And the ethanol issue, it used to be that premium had no ethanol, but that is no longer true.

Most fuels are only at 5%, but we are under the governments 'E10' phase now which means that fuel can legally contain up to 10% ethanol. It tends to be only supermarket rubbish that actually contains that at present, but all fuels will eventually. Then watch out, the troubles will really start.

[TimberCutterDartmoor]

Use only unethanol fuel, since price is no object. Available at most boat marinas. Purchase a fuel stabilizer for longer term storage.

easy-lift guy

 

Major cat out of the bag there... Damn!

 

Many people think that Premium (higher octane) petrol has, 1) a higher energy value than Regular and will therefore, 2) produce more power.

 

1) It has not.

2) It can, in the right engine, but will produce less in the wrong one.

 

High octane fuels are in fact just a little 'deader' than regular. This is because higher octane resists detonation for longer and can enable higher compression engine to fully combust their fuel without 'knocking'

 

Use low octane fuel in a high compression engine and it burns very quickly after ignition and develops it max pressure too soon in the cycle resulting in a waste of energy and a 'knocking' or 'pinking' which causes engine damage.

 

A high octane fuel resists the temptation to burn and expand too rapidly, which means the power is released progressively past TDC and downwards on the power stroke giving max efficient energy usage and max power.

 

But high octane fuel in a lower compression engine results in the burn being too slow and energy being wasted towards the end of the power stroke, resulting in loss of power.

 

Standard saws have compression ratios suited to regular fuel, so using premium is counter productive. Only Spuds ported and lowered squish saws may benefit from high octane.

 

And the ethanol issue, it used to be that premium had no ethanol, but that is no longer true.

Most fuels are only at 5%, but we are under the governments 'E10' phase now which means that fuel can legally contain up to 10% ethanol. It tends to be only supermarket rubbish that actually contains that at present, but all fuels will eventually. Then watch out, the troubles will really start.

 

Yes, what I was thinking - might it suit saws with pop-up pistons etc...

[jomoco]

I'm in the thick of SoCal, and can purchase a High octane racing fuel with zero ethanol in it for less than ten bucks a gallon, mix it with Stihl's Ultra Synthetic Oil in the silver bottle, and presto, premium chainsaw mix with a shelf life of two years stored in a sealed metal container!

 

Airports n marinas are your best options for purchasing chainsaw friendly fuels that are conducive to stayin on the pipe n revin right, IME.

 

Jomoco

[Mark Bolam]

How can I rag the arse out of most of my saws every day using supermarket petrol and Stihls cheapo one shots and average 10 years out of them?

I'm just curious how the fuel snobs see it?

I want to cut timber, not fly to the moon.

[Mull]

How can I rag the arse out of most of my saws every day using supermarket petrol and Stihls cheapo one shots and average 10 years out of them?

I'm just curious how the fuel snobs see it?

I want to cut timber, not fly to the moon.

 

 

 

Your Waitrose fuel must be decent quality, might even get you to the moon! No timber there I'm told!

[JLA Arborists]

How can I rag the arse out of most of my saws every day using supermarket petrol and Stihls cheapo one shots and average 10 years out of them?

I'm just curious how the fuel snobs see it?

I want to cut timber, not fly to the moon.

 

 

Exactly. If you can't afford a new saw every now and again your business plan needs looking at. Write them off over 2 years then any extra years is money in the bank. For example

Stihl ms 362 18" bar = £613.20

2yrs working days = 450

613/450 = £1.36 per day when you look at it like that