Octane fuel degradation

[M61A1]

Aren't we supposed to keep tanks full to prevent condensation?Anyway......I've taken to keeping mininum fuel in the aircraft (98oct) and putting it in the car after a few weeks if not used.

The car does NOT like it at all......and fuel economy drops off substantially. Not sur if this is because of the quality of the fuel or the fact I normally run 91 in the car..

I would think that by the time you put it in your car, all the good stuff has gone. I will not put anything less than 98 in my car, as I get around 100 k's or so more from a tank than using the lower octane. That would of course be assuming your car has modern electronic engine management.

 

 

[facthunter]

Many cars will get better mileage on high octane than lower. Probably all late ones will.

 

Filling the tanks to full was done to prevent condensation in training aircraft where the extra fuel would not ever be a problem weight wise.

 

Plenty of planes today can not have full fuel with a reasonable load on board as well, or they are overweight.

 

It is worth remembering the only time you really know how much fuel is on board your plane is when it is FULL or when it is EMPTY, or when you add or remove a known quantity from the tanks. Nev

 

 

[Guest Fred]

I reckon that buying 98 premium from quiet country servos is not a good idea as I have found a year ago trying to start my 447, which was always

 

sensitive to stale fuel,would not start when purchased there.Then 2 weeks later I bought 98 fuel from a busy servo on the main Hwy where fuel is more replenished often,and started first go.The 91 would be ok from the quiet servos,but not 98,your just wasting extra money

 

 

[Downunder]

I keep being told my car should go further on premium but the fact is it doesn't.

 

After 9 years and 275 000k's, 80% highway, normal 91 octane is the prefered fuel.

 

I get 10 to 20 percent less kms on premium...........

 

 

[facthunter]

I would think that was unusual. Perhaps check the codes on the engine? Nev

 

 

[Downunder]

Yep, unusual but I don't mind. Next year I'll clock up 10 years from new and probably 300 000kms.

 

Might be time to retire it. Except for a clutch, the little hyundai has never missed a beat.

 

Easily the best car I've ever owned.

 

Would have been happy with 5 years out of it but it just won't die........

 

 

[facthunter]

It doesn't owe you much now. It's surprising what mileage you can get out of a car if it warms up quickly and gets the oil and filters it needs. Nev

 

 

[Downunder]

Yes, I like to get it warm first. Seems "old school" and I don't get much interest when trying to convince others.

 

 

[turboplanner]

Great philospohy by Dr Rogers BTW