Fuel Longevity?

[BGIII]

How long is today's premium fuel good for? I am thinking about topping the boat off soon in an effort to hedge against potential summertime gas price manipulations, but I don't want a tank full of chit come June either. Am I good for 60-90 days? Tanks are pretty much empty as they sit right now.

[Chris]

Bad idea. Most likely you have winter-blend fuel in your boat. It's designed for colder weather. Summer fuel has additives that raise its vapor pressure. This keeps fuel from boiling into a gas when sitting idle inside of a fuel line on a hot engine.

Besides, who gets more than an afternoon out of a boat full of fuel? ;)

[BGIII]

When does summer blend become available up here?

[Ratickle]

The interesting thing about Michigan, is that it is not required in West Michigan because we are currently clean...

However, it is required in Chicago and almost all of our gas comes through the Chicago pipeline and we end up using the required blend for that area.

I'll have to see when that is, but I believe it's the same as SE Michigan.


SE Michigan Summer Time Gasoline in effect June 1

With the long awaited return of our Michigan summer comes the extra measures required to monitor ozone and reduce harmful smog levels in Southeast Michigan.

The Michigan Department of Agriculture (MDA) is charged with enforcing ozone protection measures in accordance with Michigan's Motor Fuel Quality Act. This environmentally friendly program, started in 1996, will be mostly transparent to consumers, who may notice a slight increase in fuel efficiency using the slower to evaporate gasoline. Gasoline stations in the eight - county Southeast Michigan area, however, must sell only the summer-formula gas and meet other state and federal requirements. Use of the reformulated gasoline will prevent the release into the atmosphere of an estimated 28 tons of smog-causing compounds per day.


The Act requires that gasoline sold or dispensed in Lenawee, Livingston, Macomb, Monroe, Oakland, St. Clair, Washtenaw, and Wayne counties from June 1 through September 15 each year can not exceed 7.0 pounds per square inch (psi) vapor pressure. (MCL 290.650d). During this period MDA inspectors will conduct on-site testing and collect fuel samples for laboratory analysis. Fines and other sanctions may be levied against those found in violation of the 7.0 psi requirement.

[t500hps]

ethanol based fuel starts to deteriorate in just a couple weeks. Couple years ago I blew a motor and was off the water for just 5 weeks. With the computer hooked up to merc software out on the water we were getting a knock that went away after we hooked up a 5 gallon can with fresh fuel.......I'm not running 90 day old fuel in my boat ever again!!!

[Ratickle]

ethanol based fuel starts to deteriorate in just a couple weeks. Couple years ago I blew a motor and was off the water for just 5 weeks. With the computer hooked up to merc software out on the water we were getting a knock that went away after we hooked up a 5 gallon can with fresh fuel.......I'm not running 90 day old fuel in my boat ever again!!!

Had no idea it was that fast.

[BUIZILLA]

don't laugh, but 4-6 weeks is shelf life...

[Ratickle]

don't laugh, but 4-6 weeks is shelf life...

So the old fuel should be pumped out, mixed half-n-half with new premium, throw in some additives, and burn in the garden tractor?

[Chris]

There's a difference between what is EPA mandated for emissions and the basic additives the refiner puts in. They don't make formulation changes only on EPA requirement. If they didn't put vapor stabilizers in, tens of thousands of cars wouldn't start that afternoon. It happens fairly often around here- it can be 20 degrees one day in March and 75 degrees two days later. Alot of cars hot-soak and vaporlock on those days, A few years back my wife went out to lunch and called after- car wouldn't start. I drove out, hit the test valve on the fuel rail and got a ton of vapor out of it. Car started right up afterwards.

[Ratickle]

There's a difference between what is EPA mandated for emissions and the basic additives the refiner puts in. They don't make formulation changes only on EPA requirement. If they didn't put vapor stabilizers in, tens of thousands of cars wouldn't start that afternoon. It happens fairly often around here- it can be 20 degrees one day in March and 75 degrees two days later. Alot of cars hot-soak and vaporlock on those days, A few years back my wife went out to lunch and called after- car wouldn't start. I drove out, hit the test valve on the fuel rail and got a ton of vapor out of it. Car started right up afterwards.

Do the refiners start putting the additives in before the mandated dates?