Blew my coolant pipes almost one year ago and due to starting a new company at the time and living off savings I didn't find it a prudent investment to pay to repair the car (and replace the clutch, water pump, and all the other little goodies when you drop the engine).

Therefore the car sat in storage with about 3/4 of a tank of 93 in her for about a year now. We have a 10% ethanol blend here in Nebraska for whatever it's worth. I didn't put any Stabil or additives into the car. Should I add some now and some octane booster as well? Or pay the dealer to drain the tank?

Regardless even if I didn't drain the tank I wasn't planning on getting into boost until the tank was used up and fresh gas put in. Just putter around burning it up. Do you think that would be ok?

A little stabil/octane booster + 1/4 of fresh gas right away and no boost until the tank is gone?

 

Definitely drain that old crap out of there! I wouldnt even run 1 year gas in a lawn mower much less a 911.

 

off with 91/92/93 or 100 if you can get it. If I could get 100, I would probably drive it normally, if I could only get 91-93, I would still stay out of boost mostly until my next fill-up.

Just my opinion.

 

Drain it. Here is how you do it https://www.6speedonline.com/forums/...fuel-tank.html

 

drive it easy until you fill up next. Consider a fuel filter sooner than later as wise maintenance

 

Fuel filter was replaced 34 miles before the coolant lines let go...

 

If you run the old gas thru replace the filter after - sediment and chemical changes in fuel. IMO drain it.

 

Probably best to drain/remove the fuel.

My experience with a family member's new Infiniti was after about 6 months the fuel was stale. The car was not driven as she was on the hospital (for nearly a year).

As I said above after about 6 months with the same fuel in the tank I borrowed the car -- with my family member's permission -- to use to drive my elderly parents around. The engine fired right up and idled just fine but the car/the engine felt a bit flat. I was not used to the car so I thought it normal.

Finally the fuel tank got low enough I needed to add fuel. Filled up the gas tank with Shell V-Power -- the car owners manual said to use premium and the family used premium -- and the engine was transformed.

The change in the engine's performance was quite remarkable. The engine still fired right up and idled just fine but the engine no longer felt "flat".

This was after just 6 months of time. I would think after a year the fuel in your car is more than just stale.

You really can't "unstale" fuel. It loses octane and detergent capabilities and won't burn as cleanly. This increases fuel injector and engine deposit build up.

Even if you were willing to subject the engine to this it is hard to drive the car in such a way that stale fuel doesn't matter in other ways.

One might think avoiding boost but my experience with my 996 Turbo is the thing can make boost under rather sedate usage. Granted we are talking about 0.2 or 0.3 bar boost but still it is making boost.

Low RPMs under normal circumstances can have the DME attempt to really increase the timing. (I have observed the timng to advance to 35 or more degrees BTDC.) But with stale fuel it may not be able to deal with the advanced timing and the DME will of course retard timing. The problem is if the fuel is stale enough the DME may not have the range to dial back timing enough and the engine could suffer from detonation.

Really with a year's time the fuel is stale and really stale fuel in a high performance car is bad fuel.

Were it my car I would go to the expense of having the old fuel removed and filling the tank with fresh premium fuel. After going through a half to a full tank just to be sure things are ok I might be tempted on the 2nd tank to add a bottle of Techron to really remove any fuel/injector/engine deposits. 'course, if you use Techron the recommendation is to after it is used up to change the oil/filter.

 

i would extract the fuel or drive easy without boost.