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Can I mix Ethanol and NON-Ethanol gasoline?

I have a 2010 Toyota Tundra and a new boat with 30 gallons of NON-Ethanol gasoline that I don’t want to let sit while the boat is stored for 6 months. Since the Tundra uses E10 gasoline regularly, will mixing in NON-Ethanol gas pumped out of the boat cause any problems for the Truck? The boat is new so the NON-Ethanol gas should be clean. The boat gas has also been treated (storage levels of 1 oz per gallon) with “Yamaha Fuel Stabilizer & Conditioner Plus” as well as Yamaha “Ring Free Plus Fuel Additive”. [The “Ring Free” additive is designed to keep my Yamaha F150 Outboard Motor from building carbon deposits, etc.] I have a friend who does this regularly with his boat and Ford truck, but in his case both the truck and boat use E10 gas. I use NON-Ethanol gas in the boat since it is available locally for recreational vehicles. I need to do something useful with that 30 gallons of gas, but I also don’t want to do anything that would mess up my Truck!!! Comments? Advice?

The truck will enjoy the real stuff. You might get better fuel mileage on straight gasoline.

Sure! You can put non-ethanol gas in your truck. I wish they would get rid of ethanol gas.

But now they’re bumping the ethanol contant in gasoline up to 15%. And the auto makers are warning against this.


The two fuels are compatible and interchangeable…

The fuels are ok but you might want to check with Yamaha to make sure that the Yamaha Ring Free additive is ok to use with a cat converter. A phone call or an email to Yamaha should get what you need to know. If the boat and fuel are stored in a cold winter area, you could just leave the fuel stored and use it when the weather clears and you can go boating again. Make sure that the fuel tank is not vented to the atmosphere. I store a car in the summer for approx that time and do not use a fuel stabilizer and have no problem starting the engine so I can’t recommend the stabilizer.

I use mostly ethanol-free gasoline for our cars. That is the real stuff; 10% ethanol gasoline is tolerated.

The reason for storing a boat with a full tank of stabilized gas is it reduces condensation during storage. This means you don’t get corrosion and water in your gas tank. If your boat uses a metal gas tank this is more important than if it has a plastic tank. If the gas will be used within a year of purchase and treatment with stabilizer it will be fine staying in the boat.

I don’t think I’d mess with the hassle of transferring the gas to the truck from the boat unless you are not going to be using the boat within the next 9+ months from now. If you drain the boat you’ll just have to spend the money on fueling it up again when the boating season starts, so money wise it is a wash.;

Use the non-ethanol gasoline in your Tundra and enjoy the benefits of increased mpg, no problems. When warm weather approaches you can refuel your boat with fresh gasoline.

Parking a boat for an extended length of time often causes problems in the carburetors. The fuel in the tank may not deteriorate significantly but the fuel in the carburetors often evaporates and leaves a crust similar to a heavy coat of shellac. If the engine is run periodically the problem can be avoided. You might check Yamaha’s recommendations regarding off season storage. The manufacturers often have a procedure for running the fuel system dry before parking it. That preparation is more important than emptying the tanks now and refilling them next season.

Isn’t 10% ethanol gasoline a mixture of ethanol and gasoline?? Of course you can use it.

And for those who think E10 is a new idea:

Yes. It’s an old idea and it’s still a bad idea.

Ethanol gas IS already mixed. By adding NON ethanol gas…it’s just diluting the ethanol mix you already have.

THANKS EVERYONE! I thought this was the answer, but I just wanted to make sure. This site is great!
Wha Who?: Good advice - I called Yamaha Customer Service and the guy I talked to said that he runs Yamaha Ring Free additive in his personal truck regularly with no problems w/ the cat converter.
Uncle Turbo: I agree, but my problem is that some of that gas was put in the tank a year ago. Not much really (65 gallons 1 year ago, added another 30 gallons this fall, and 30 gallons now remaining) but it is a new boat and I am very paranoid about gas quality in my new engine. [Anyone want to work out how many gallons of one year old gas would be in that 30 remaining gallons? There is a story about why I could not determine how many gallons were remaining before I added the fresh 30 gallons. Let’s just say that my fancy new electronic “to the 10th of a gallon” fuel monitoring system is going back to the marine electronics shop this spring!!]
Red Fox: I also agree - I have personal experience with clogged carburetors after storage!! But, of course, the new engine uses Electronic Fuel Injection. Same problem is possible, but at least unlike a carburetor the EFI system is not open to the atmosphere so much (I don’t think). Yamaha’s owner’s manual does actually recommend draining the Vapor Separator Tank (VST) as part of the winterization process. Apparently however, according to both the Yamaha Customer Service Rep I spoke to on the phone today AND my local Yamaha Certified Service Center manager, even THAT is no longer a valid procedure! It used to be you used “fogging oil” in a spray can through the air intake in an outboard until the engine bogged down and then removed the plugs and sprayed the fogging oil into each cylinder - turning the engine over briefly between cylinders - and then replaced the plugs. NO more! The new procedure is to use Yamaha EFI Fogging Oil in a bottle. It contains the fogging oil, fuel stabilizer, and Ring Free all together. You pull the fuel line off the boat’s 10-micron water separating fuel filter (You DO, for heaven’s sake, have one of those to protect your EFI outboard engine, don’t you? … ), and stick it into a two gallon mix of the EFI Fogging Oil and gasoline and run the engine. When the two gallons of the magic mix is sucked up and ingested by the engine you are done and can reconnect the gas line. The entire fuel delivery system (less air intake, of course, but I hear that those are pretty much plastic components now) is treated. No need to drain the sealed VST, according to Yamaha. This stuff is changing so fast the manual is out of date before you get it! But, progress and all that - I plan to try the new procedure Real Soon Now.

Oops, forgot to mention that the “old” gas remaining in the boat tank is actually still good right now - I just don’t want it to sit unused for another 4+ months this winter. I was running it in the boat a week ago and I am sure the Truck will be happy with it. I always use fuel stabilizer when I put gas in the boat and it keeps gas (especially NON-ethanol gas) in good condition for at least 1 year.