View Full Version : Would you run year old gas in car ?

05-21-2014, 03:14 PM
I have a 1992 BMW 325is that I have not driven since last July and the state inspection is due this July . So the gas is a year old , I know I would need to add some type of additive that would remove water before starting .The car has about 7 or 8 gallons of gas in the tank . To pump the old gas out , would be about an hour job ( remove lower back seat - easy, remove fuel pump - not hard to do , pump out old gas - easy , install fuel pump , install seat , put in fresh gas ) . What would you do ? thanks in advance for advice .

05-21-2014, 03:15 PM
Too late for the gas additives. Fill er up and hope for the best.


05-21-2014, 03:26 PM
You could add some Seafoam...that may help a little.

I agree with WakeWise, run it. We do this all the time with old Porsches we find. Usually, they start and run ok on the old gas.

I would carve out an hour and run your BMW down the road, burning up most of the old stuff and then refill with fresh gas.

05-21-2014, 03:33 PM
I would fill it up drive it until almost empty and fill it up again before going in for testing.

Miss Rita
05-21-2014, 03:44 PM
There shouldn't be any water in the tank, since it's sealed to the atmosphere.
I would fill it with premium E-10 and add a can of Seafoam. If there is any water in the tank the ethanol in the fuel would bind with it so that it goes out the exhaust.

05-21-2014, 04:36 PM
Mostly what Rita said.

There is no water in the gas originally. The water comes for condensation of the air(as temperature changes in the tank) above the gas. So more gas originally in the tank, the better.

Depending, if you have to do an emission test. No additives, as it could cause a bad reading.

If it runs on existing gas. (Bet it does!) Drive it near empty (not empty, just in case), put in new gas. New plugs, with good wires, charge up the battery to 100%. Clean air filter. Good to go.
Drive the car some more, to get the new fuel in the system. Disconnect your battery, as it may clear the cars computer (not sure about BMW) Hook it back up, drive to get it inspected.

If no emissions test, put in gas and go. My boat sat, from Sept to last weekend, near empty tank. Put in 15 gallons, skied all afternoon.

Main difference is, if emission test, is requiredfor your car.

05-22-2014, 07:16 AM
X2 on the Seafoam....that stuff is even great on pancakes!!!

05-22-2014, 08:16 AM
It will be fine. Just don't flog it While on the old gas.

I would change the oil first though. I would be more concerned with that then the fuel. Ad stabilizer next time as well. I've been trying to do this if I know something will sit for more than 3 months.

05-22-2014, 09:39 AM
Trick is if you go to clear the computer to make sure to drive it around for awhile so the computer completely resets. If they hook it up and see the computer has been cleared recently they will reject it and make you do it all over again.

05-22-2014, 11:12 AM
thanks for the replies , I think that the oil should be okay , the car has Red Line Syn. oil in it and at $11.95 a quart I hope it is still good but I will change the oil soon . I had planned on driving the car more this past year but that just did not happen . I will add stabilizer this time ! thanks again for the replies

05-22-2014, 12:26 PM
The oil can turn acidic with time/fuel dilution. That's the main issue. Pits the bearings and eats the seals.

At the very least, change the oil filter. Those WILL breakdown over time. I would not stretch it out more than a year.

05-23-2014, 12:47 AM
Ethanol turns to gunk and destroys everything. If its 100% real gas, no ethanol then you're fine.