Winter Storage Fuel Mix

[jwwseville60]

Hi all!

For my old Caddies and Lincolns, I've come up with a dandy winter storage mix.

I fill the tanks to 3/4 with 92 ethanol fuel.
I add 6 ounces of Marvel's Mystery Oil to help with gas/water separation. More if you want.
I add 3/4 of the recommended amount of Stabil 360.
I finally add two gallons of 110 octane leaded race gas. The good amount of T-lead helps preserve the fuel for my 3 -1/2 months of winter here in VA. Takes me 3 months to burn off all the winter gas mix in all the cars. (Total 6.5 months).

At spring start-up, no problems! The fuel mix is good for a year or more.
Also, electric fuel pumps and return lines are highly recommended.
A garage dehumidifier is also a must.

Best,
JWW

[TJ Hopland]

Were you having issues with 2 1/2 months before you settled on this cocktail?   Do you have any winter equipment that gets stored for 9 1/2 months?   If 2 1/2 causes problems I would hate to imagine 9 1/2.   

In my area especially when ethanol was our only option I saw a big difference between the 5 month summer stuff stored over winter and the winter stuff 7 months over the summer.     Winter tends to have bigger temp swings and condensation issues in minimally insulated buildings so I would have expected the winter storage to be harder on things but it seemed like the time had a larger effect. 

[Michael Petti]

My Cadillac gets stored in Northeast Ohio for 6 months each year with a full tank of Shell V power and 1 can of Stabil good for 20 gallons. Starts in the spring with just a little prime to the carb. What purpose does the Marvel Mystery oil serve. Maybe it's a good idea.

[dn010]

Maybe it's just me, but that list seems pretty excessive. I put Stabil 360 in the fuel and let my cars sit when not driving sometimes for months on end, sometimes longer. The longest I've let a tank sit full of 87 ethanol fuel with Stabil was for around 3 years, well past the 1 year Stabil recommends, and it still ran through fine with no issue - no stale fuel smell, no sludge, no tank rust and no pinging.

[fishnjim]

I bought some of the aforementioned fuel stabilizer for the boat, a few years ago,(to try) and never had to put it in as it was a warm winter and I used it frequently through out.   The bottle of stabilizer went bad on the shelf that summer.  Turned colors and bottle shrunk up.
Caveat Emptor.
The '58 sat for almost 3 years with just plain shell high octane and started right up.   Garage is not heated, but never gets real cold, >20F, here.   Tank is stainless.
Why would anyone use something labeled "mystery" where you don't know what you putting in or what might happen.   I don't treat my equipment like that...   I spent 32 years in industry doing chemical engineering, so not a novice here.
I posted my fuel storage studies on here.

[jwwseville60]

I learned about Marvels Oil from old master mechanics. Its wintergreen oil. Its been around for 100 years so it must be pretty good.

In the old days, gasoline had more oils in it for lubrication, unlike todays ethanol gas meant for high pressure fuel injection. Marvels won't harm anything pre-1980.
Valvetrains love Marvels.

Nothing wrong with leaded race gas. Its basically what they had in the old days, leaded super. Which is usually what Cadillac recommended from 1955 on.

Of course a heated garage is ideal.

[35-709]

Marvel "Mystery" Oil --- no real mystery, just someone's idea of a clever marketing name when the product was first introduced long ago. 
Good stuff, back in the radial engine days the airlines (and others) used Marvel Mystery Oil to pretty much cure the problem of valves hanging up when the engine was under high power use and high temperatures, such as at takeoff and climb out.  Not FAA approved for aircraft use, the FAA was said to turn a blind eye to its use.  The airlines didn't flaunt it and the FAA, "didn't know about it".  The Wright 1820 powered radials on the Bull Thrush agricultural aircraft I used to fly were subject to hanging a valve now and then --- really made you sit up and pay attention when climbing over a tall power line at the end of a pass.  Using MMO in the fuel stopped all that.   

[TJ Hopland]

One thing I noticed that made a huge difference on how well things did during cold storage was if the garage is also used for daily drivers.   Most of my life my garages were not used for daily drivers, usually junk and a non daily driver if I was lucky. 

There was one winter I was renting and had to share a garage, the other person used his half of the garage for his daily driver.  Crazy right?    I had the same stuff in that garage I had in my previous and current one and they were similar minimally insulated and about 30 miles apart so same climate.  That one winter in that garage did more damage to my stuff and I think every engine had fuel and starting issues that spring than I had ever had before or since.

Difference had to be that garage door opened twice per day compared to maybe twice a month for me and there was a daily driver in and out that I would imagine contributed to some extra amount of heating and cooling plus even though it wasn't heated there was still salt and snow melting off onto the floor.  None of that flowed over and got my stuff wet directly but I would imagine maybe made the air more coastal like?

[Jim Miller]

I'm in northern Ohio and put the cars away around December 1 until mid April. I regularly use non ethanol gas and add 4 ounces of MMO per 10 gallons of gas. I've never done or added anything else and they start just fine in the spring. I do put them away with a full tank.