Use of Premium Gas in Brand New Lawnmower?

[detett1560]

Hello...I just bought a brand new self propelled mower with a Briggs and Stratton 675 Series Engine. The sales person told me to be sure and use fresh "Premium Gas" because it contains NO ETHANOL and therefore WONT gum up the fuel system which would make sense. HOWEVER, after reading the owners manual I noticed it states NOT to use Premium Fuel.

Can anyone elaborate why using Premium Gas would harm the engine...or not??

This is a brand new mower and I just want to do the best for its longevity etc.

THANKS!! :smile:

 

[Rivets]

No engine manufacturer recommends premium fuel in the engines. We started recommending non-ethanol fuel almost 2 years ago. We even install a sticker on every new mower we sell and all units we repair. 90% of our customers have followed our recommendations and we have see a drop in fuel system problems.

 

[Snapper7800597]

My gas cap is marked "85." Wonderfully dummy proof!! I too just bought a NEW ( to ME ) Snapper.... And I asked about fuel... and what's so bad about "old" fuel... and the whole thing about what the other person said about Ethanol.... I would trust the mechanic over a sales rep any day of the week!

From now on, I will only keep fuel a max of 30 days.

The dealership explained that old fuel breaks down, even with the stabilizers....Nothing, he said, will really stabilize fuel. The problem with the old fuel is the components that break down & bad stuff... will go into your engine & possibly zap it dead. After that conversation, I think I would throw fuel away rather than risk it.

Get a smaller gas can... I went from a 6 down to a 2.5 gal. It means more trips to the gas pump, but fresher gas in your machine. If you can't handle a smaller can, then toss any remainder in your vehicle after every mow. If you still have questions.. 83/85/87... contact the manufacturer directly. Happy Mowing!

 

[detett1560]

My gas cap is marked "85." Wonderfully dummy proof!! I too just bought a NEW ( to ME ) Snapper.... And I asked about fuel... and what's so bad about "old" fuel... and the whole thing about what the other person said about Ethanol.... I would trust the mechanic over a sales rep any day of the week!

From now on, I will only keep fuel a max of 30 days.

The dealership explained that old fuel breaks down, even with the stabilizers....Nothing, he said, will really stabilize fuel. The problem with the old fuel is the components that break down & bad stuff... will go into your engine & possibly zap it dead. After that conversation, I think I would throw fuel away rather than risk it.

Get a smaller gas can... I went from a 6 down to a 2.5 gal. It means more trips to the gas pump, but fresher gas in your machine. If you can't handle a smaller can, then toss any remainder in your vehicle after every mow. If you still have questions.. 83/85/87... contact the manufacturer directly. Happy Mowing!

Since posting this, I've done alot of reading on the net on this subject. Premium fuel isn't going to benefit this type of engine and will actually run hotter due to the higher octane. SO Im going to stick to what the manufacturer says and just run the tank empty and drop the carb bowl to drain the remainder out when the season is over. This way no risk of gumming up anything.

THANKS to everyone who replied! :thumbsup:

 

[possum]

I have a near new Briggs engine of that type and the book does not state anything about no premium fuel. It does state no more than 10 per cent ethanol and no less than 87 octane and unleaded. Nothing about no premium.Many gas stations in this area do not even carry 87 fuel. Many have only one 87 pump and it is either busy or empty. If no fuel over 87 could be used in Briggs engines no one would be able to sell them around here. Every dealer in a 30 mile radius here tells you to use 91 ethanol free and where to buy it. All the canned gasoline I see for sale for lawnmower engines is higher in octane than 87. Yet those companies who sell the canned gas all stand behind their product in Briggs engines. Non ethanol gas is a good idea i think if it is available. I have used both premium and regular in non ethanol and like both. I do think premium starts better. Find yourself a gas station that sells non ethanol gas and stick with it. Premium or regular.

 

[Rivets]

83/85/87???? What are these? In most of the U.S., regular gas has an octane rating of 87, midgrade gas is 89, and premium is 91 to 93. (Octane ratings are lower in the mountain west due to the effects of thin air on internal combustion.) You can get even higher octane if you get into aviation and racing fuel. I will agree that gas does break down, but the real problem is the addition of ethanol into the fuel. Many of us old guys had fuel blends in the old days which would still work fine in our engines after sitting around for six months, but it did not contain any ethanol. Ethanol is an alcohol which does two things to harm a fuel system. Alcohol is a drying agent which attracts moisture. Many of you may have used isopropyl alcohol in the past as a gas line deicer. As a drying agent it creates a problem with the non metal parts of your carb and fuel lines, drying them out and hardening them. As a moisture attractant, it draws water into the carb, which causes corrosion in the small passage ways. Why we recommend premium fuel? Because it is the only fuel that is being produced for the mass market without ethanol.

 

[detett1560]

83/85/87???? What are these? In most of the U.S., regular gas has an octane rating of 87, midgrade gas is 89, and premium is 91 to 93. (Octane ratings are lower in the mountain west due to the effects of thin air on internal combustion.) You can get even higher octane if you get into aviation and racing fuel. I will agree that gas does break down, but the real problem is the addition of ethanol into the fuel. Many of us old guys had fuel blends in the old days which would still work fine in our engines after sitting around for six months, but it did not contain any ethanol. Ethanol is an alcohol which does two things to harm a fuel system. Alcohol is a drying agent which attracts moisture. Many of you may have used isopropyl alcohol in the past as a gas line deicer. As a drying agent it creates a problem with the non metal parts of your carb and fuel lines, drying them out and hardening them. As a moisture attractant, it draws water into the carb, which causes corrosion in the small passage ways. Why we recommend premium fuel? Because it is the only fuel that is being produced for the mass market without ethanol.

Where I live here in NC..even Premium has 10% Ethanol...the purpose of buying Premium would be to avoid having the Ethanol in it but thats not the case around here. Buying Premium will do me and my mower engine no good.

I have a near new Briggs engine of that type and the book does not state anything about no premium fuel. It does state no more than 10 per cent ethanol and no less than 87 octane and unleaded. Nothing about no premium.Many gas stations in this area do not even carry 87 fuel. Many have only one 87 pump and it is either busy or empty. If no fuel over 87 could be used in Briggs engines no one would be able to sell them around here. Every dealer in a 30 mile radius here tells you to use 91 ethanol free and where to buy it. All the canned gasoline I see for sale for lawnmower engines is higher in octane than 87. Yet those companies who sell the canned gas all stand behind their product in Briggs engines. Non ethanol gas is a good idea i think if it is available. I have used both premium and regular in non ethanol and like both. I do think premium starts better. Find yourself a gas station that sells non ethanol gas and stick with it. Premium or regular.

In my operators manual it states NOT to use "Premium fuel" but doesn't mention what octane rating they consider "Premium" Hence my original question. You are right tho, it would be nice to find NON ETHANOL GAS but no one around here sells it....even the Premium I found out after calling around has Ethanol in it.

 

[Rivets]

I think you should do a little more research, because premium fuel does not burn noticeable hot than regular. It is designed to burn slower, to resist knocking and pre detonation in the cylinder.

You say there are no non ethanol stations in your area. According to this registry there are 284 in NC.
Ethanol-free gas stations in the U.S. and Canada

Please make me smarter, and tell me which engine manufacturer says not to use premium.

I agree with you on one thing, premium is not going to make your engine run better. No one ever said that. Want I am saying is that in my experience of over 40 years working on engines, using non ethanol fuel will save the owners of today's small engines money, and lost time.

 

[Carscw]

The higher the octane the less shelf life it has.

I run 120 at the track if you burn less than half a tank in one night you drain out half of what's left and add fresh gas to it next week.

7 days and it gets that old gas smell.

The higher the octane the bigger the explosion in the chamber. And less gas not burned

(( racing is the only sport that you need two balls ))

 

[motoman]

Higher octane gas contains more and better additives . It is developed to control detonation in high compression engines. There are no explosions in a combustion chamber if the engine is running properly , only controlled flame fronts. High octane gas is a waste of money in cars and tractors which do not require it. I dump small quantities of aged two stroke mix with sta-bil into tractor when I know it will be used up- no problem.