New gasolines and storage

[Chinewalker]

Well, with the new formula fuels coming down the pike, the new Mercruiser recomendations for extended storage have been released. The new fuels in California and AZ have approx. 35% Ethenol. This means the evaporation factor has nearly doubled and, yes, it doesn't store for more than 15 days before it starts loosing octain and the RON #'s start to drop. The best way to store your boat with aluminium tanks is empty with a stabilizer to keep the moisture out. Remember that the new engines, 496's and 500 EFI's will run a bit different also.

G-man

[Rude]

what do you mean that the 500efi's will run different? do i need to be running an octane boost after 15 days?

[Essex502]

Thanks for the info. Did you get that from the Mercury Marine site? What about a 2000 502 Mag MPI?

[Chinewalker]

As for the 500 EFI, you just want to makke sure that the fuel is fresh. Octane boost won't hurt it if the fuel is old. Samer goes for the 2000 502 , you are ok with regular fuels such as 89 or 92 octane. I would not recomend runing octane boost in the 502 however. It will have a tendancy to detonate.

[Rude]

so you're saying i shouldn't run any type of octane boost if the fuel is fresh? i've been running the 91-92 octane, should i be using this grade or the lower grades?

[Essex502]

chinewalker - I have had the gasoline in the tanks since September but with Sta-Bil added. Are you saying that isn't a good practice? I always thought that adding Sta-Bil and filling the tanks was the best method to reduce moisture build-up in the fuel.

[Rude]

E502, i'm not sure what to think either. i've heard both ways, some say to store it empty while others say to store it full. i guess you've got a 50/50 shot at getting it right http://www.lasvegashotboats.com/iB_html/non-cgi/emoticons/ohboy.gif

[Essex502]

True enuf, Rude! I have seen both methods though the full tanks makes sense from a physical standpoint as with less air volume the amount of condensation, I presume, would be less. I understood from my Amsoil days that the condensation broke down the oil additive package and I would assume have the same kind of effect on the fuel.

[Chinewalker]

The problem is that the new fuels will start to detiorate after 21 days. The grade of fuel really doesn't seem to matter. Definately use Sta-bil with any amount of fuel. The best way now is to keep the tanks low with a high concentration of fuel stabiliser.

[Essex502]

Is there any harm in exceeding the mixing formula for the Sta-Bil? I don't remember the exact mix but let's say the instructions state: "One bottle (8 oz) treats 20 gallons." and instead you use 2 bottles (16 oz.) for the 20 gallons. Does that higher concentration - assuming not adding additional fuel to the mix at a later date - harm anything in the motor if burnt at that ratio?

Inquiring minds want to know....

[Chinewalker]

Maybe not double the dose, but I would definately get used to using about 1/2 more than they say. One thing to keep in mind is that the water seperating filters will need to be changed more often.

G-man http://www.lasvegashotboats.com/iB_html/non-cgi/emoticons/confused.gif time for another drink!

[Essex502]

Thanks, CW! We'll find out how it did come April 12th when we get the boat in the water for the first time this season!