Fuel for Onan Generator 4.0 BFA

Ken · August 03, 2013, 01:41 PM

I am aware that Onan manual states regular gasoline. I can purchase premium (marked) off road gas for considerable less than regular pump gas. I would not think there would be any problem running premium gas in gen-set? Am I correct?

Stripe · August 03, 2013, 04:19 PM

I don't suspect it would damage anything on the genny.. I have used a higher grade of fuel in my RV and the genset shares the tank with the engine, have not noticed any problems as yet, but only have had the RV a few months..

Ken · August 03, 2013, 08:54 PM

Thanks. I am sure it is ok. Just thought maybe someone was aware of something that I was not. Had several motorhomes but first gen-set.

legomybago · August 05, 2013, 01:15 PM

Try to get yourself in the habit of running the genny every few weeks with a load on it (AC or microwave on) for 15-20 minutes. Keep the fuel moving, or drain fuel when in storage

DaveVA78Chieftain · August 05, 2013, 01:56 PM

Hmm, I have heard of "Off Road Diesel" for tractors, road equipment and such but "Off Road Gasoline" is a new one.

Dave

Oz · August 05, 2013, 03:12 PM

"off-road" = "moonshine"

Ken · August 05, 2013, 05:50 PM

Here in BC Canada we can buy gasoline (marked with purple dye) called marked gasoline. Because it is designated for farm or off road use only, it is not subject to the road tax included in gasoline intended for highway use hence it is cheaper. One local station sells marked premium for $0.13 per litre less than regular gas. People use in in boats, ATVs etc.

EarlJr · August 05, 2013, 06:34 PM

We can get off-road gasoline here as well. It has lead in it and isn't allowed for on road use. Have to go to a distributor to get it, and they won't pump it into an "on-road vehicle." It's basically race fuel, and I couldn't see running it in my gen set (especially at $8 or $9 a gallon).

Ken · August 05, 2013, 08:07 PM

Ours is the very same gasoline as purchased from the premium pump for highway use. The only difference is the addition of purple dye to indicate that " Road tax" has not been paid on it. It is illegal to pump it into a highway vehicle unless it has a " Farm" plate on it designating a farm vehicle. I apologise if my terminology appears to have been so confusing. My question was simply about the running of premium gasoline in an Onan generator that calls for regular gasoline.

DaveVA78Chieftain · August 05, 2013, 09:31 PM

premium will be fine

Ken · August 05, 2013, 09:42 PM

Thanks. In reply to Mark's comment re moonshine, all I can say is " I wish!!!"

Froggy1936 · August 05, 2013, 10:51 PM

They Do the same thing with oil for heating (dye) its the same as diesel but the road tax as not been paid Frank

bluebird · August 06, 2013, 10:03 PM

Why? I ran a 1980 BFA for two years almost every week end on regular unleaded with 10 percent ethanol, without problems. We sometimes would run it 8 to 10 hours nonstop if the weather was hot. I needed the air conditioner, on those days in July, Aug. It was running just fine when I sold the coach a few years ago. Premium fuel may make it run hotter than regular fuel as it burns slower, more heat.

Ken · August 06, 2013, 10:44 PM

Only reason I was considering running premium is because "marked" premium is quite a bit cheaper here than regular road gas.

bluebird · August 06, 2013, 11:00 PM

I could see you wanting to use it if it's cheaper, but watch the heat. If the exhaust manifold starts to glow at the head, it's too hot.

MotorPro · August 07, 2013, 07:41 AM

Premium fuel is only differant in its ability to prevent detonation. It has no more btu's than regular gas thus burns no hotter. You can always use higher octane with no damage except usually to your wallet.

Ken · August 07, 2013, 12:49 PM

Thanks everyone for the input.

bluebird · August 07, 2013, 06:15 PM

Quote from: MotorPro on August 07, 2013, 07:41 AM
Premium fuel is only differant in its ability to prevent detonation. It has no more btu's than regular gas thus burns no hotter. You can always use higher octane with no damage except usually to your wallet.

And how do you suppose it detours detonation? By burning slower not hotter. If higher octane fuel is ignited at the same time as it's lower octane fuel, the heat will be in the cylinder longer, and that could cause an air cooled engine to over heat. Engines operate better with the rated octane that they were designed for. Even a race engine. When I ran a gas engine in the race car with 112 compared to 100, I had to cool a few minutes more with the 112, and it didn't make any difference in et or mph. I'm not a motorpro, but I've been messing with um for close to 50 years.