storing car for a couple of month, what to do with gas in tank?

[mikey19]

Hey guys,

so im planning to store my car of a couple of month, in a garage.

I already bought a bottle of STP fuel treatment to prevent rusting,etc. Just wondering if I should have my tank full or have it near empty.

I thought that it would be back to have a full tank of months old gas to burn it off after I start driving the car again...
so should i leave my tank near empty so I can just add fresh gas at a nearby station when I'm driving the car again?

thanks

[Space Ghost]

They say leaving it full helps prevent condensation in the tank.

[M3 Montreal]

Originally Posted by mikey19

Hey guys,

so im planning to store my car of a couple of month, in a garage.

I already bought a bottle of STP fuel treatment to prevent rusting,etc. Just wondering if I should have my tank full or have it near empty.

I thought that it would be back to have a full tank of months old gas to burn it off after I start driving the car again...
so should i leave my tank near empty so I can just add fresh gas at a nearby station when I'm driving the car again?

thanks

Put the highest octane rating fuel you can get your hands on and buy "Fuel Stabilizer" and follow the instructions on that. Once the Stabilizer is in your tank run it for a while so it can get into the cylinders.

2 months is not long so ask someone to start it once every 3 or 4 weeks and dont lock it (in a home garage of course) so the alarm doesnt drain the battery.

Otherwise... Get a trickle charger if you cant have it started and make sure to overinflate the tires.

I just took mine out of storage yesterday... Ohhhhhhhhh so sweet to drive it again!

[BobsM3Coupe]

If it were my car, I would make sure the tank was filled and also add the correct amount of fuel stabilizer. Although for 2 months, even adding the fuel stabilizer may be a bit much, but it can't hurt. I would use a battery tender. And I certainly wouldn't want anyone to start the car to just let it idle in the garage. That is one of THE worst things anyone can do to any vehicle. All that does is dump huge amounts of condensation into the oil and exhaust system because the engine never comes up to proper operating temperature. Even though the temp gauge may show the normal zone, only a 15 minute run on the freeway will warm up the engine properly and burn off the condensation.

[JCtx]

In summary:
- NEVER run a car while in 'storage' without driving it at least 15 miles. The M3 has a lot of oil, and it takes a while to reach full operating temperature, and to burn all condensation formed up to that point. Otherwise you'll be rusting your engine internals and exhaust system; not smart. It's MUCH better not to start it at all, even for prolonged periods of time.
- For 2 months it's not even necessary to put fuel stabilizer on the fuel, but since it can be longer than that, I recommend it. Once treated, fuel will stay fresh for ONE YEAR, so no worries there. Just make sure to drive the car for a few miles to ensure stabilized fuel reaches all the way to the injectors.
- Always store a car with a FULL tank of gas, to avoid condensation.
- And leave battery on a 'smart' trickle charger, but I prefer to charge it every 2 weeks myself, rather than leave it connected all the time, but that's a matter of preference. M3s are not easy on batteries while in storage, but once all systems are in 'sleep mode', it gets discharged a lot less.

And also not mentioned, inflate your tires to at least 35 psi to avoid flat spots. Oh, and make sure there's NO FOOD in your garage, to avoid rodents making a nest out of your car. That's all man.

[SoreHead]

Stabilizer and fill the puppy up to prevent condensation in the tank.
And the advice on the tyres too. Over inflate as Montreal said. Don't forget that bit as the 2 months will have more affect on that then the fuel.

Fresh fuel should be good for about 5-6 months. Stabilizer will extend that to about 2 years if done correctly.

[M3Bliss]

Originally Posted by elp_jc

In summary:
- And leave battery on a 'smart' trickle charger, but I prefer to charge it every 2 weeks myself, rather than leave it connected all the time, but that's a matter of preference. M3s are not easy on batteries while in storage, but once all systems are in 'sleep mode', it gets discharged a lot less.

The smart charger idea is important. I had one on my Cayman S when in winter storage and it only charges the battery when it starts to loose charge otherwise it turns itself off. Another idea someone in the Cayman Club had suggested (and I used) was to put squares of carpet under each tire; it protects against excess moisture creeping into the car.

[H8cold]

I though you should keep gas to the lowest level, so you can fill it with freah gas so you don't have bad gas for a long period of time. How do you know if you have Condensation in your gas, maybe it's a good idea to add some dry gas like Isoheet. Any thoughts?

[SoreHead]

Originally Posted by H8cold

I though you should keep gas to the lowest level, so you can fill it with freah gas so you don't have bad gas for a long period of time. How do you know if you have Condensation in your gas, maybe it's a good idea to add some dry gas like Isoheet. Any thoughts?

With piston aircraft you see it in the fuel sample you take from each tank. Then just sample away until it's gone but not sure how you would check in a car.
Full is definitely the way to go to avoid condensation as long as it's only going to be in there for less than 6 months (say 4 for extra safety). However, you can leave it in for considerably longer if you use stabiliser.

You get condensation in any container with liquid when there is a rapid change in temperature so it's actually quite unlikely to happen anyway as the temperature tends to change quite slowly inside the fuel tank. Better safe than sorry and one of the main things to do to avoid it is to fill up and get as much of the air out as possible.

[osteome]

Originally Posted by H8cold

I though you should keep gas to the lowest level, so you can fill it with freah gas so you don't have bad gas for a long period of time.

With luck, I will pull the M out of storage in about 2 weeks. I left the tank filled with fuel stabilizer as recommended.

I fully intend to burn through the tank in "record speed", so I am not concerned with the bad gas. If I get more than 13MPG on the tank of storage gas, I will disappoint myself!

[mikey19]

so where do I get this "fuel stabilizer"? does the STP branded fuel treatment bottle from walmart count?
or should I look at stores like Autozone or Advanced Auto Parts?

ill already inflated my tires to 35 psi cold, so that shouldn't be a problem.

thanks for the advice!

[Pete The Greek]

this has been discussed many times, but heres a pretty good post I found:

Originally Posted by drburton

Having a Boxster which has been stored over Minnesota winters, I have some experience with this. This was written by someone on a Boxster forum (don't recall who).

1. Change the oil just prior to storage. Oil absorbes moisture (a natural byproduct of combustion) and if old oil is left in the motor, moisture will evaporate out of the oil and condense on the engine internals causing corrosion. Also, oil becomes acidic with use and should be changed for this reason also. Change oil, start engine and run just long enough for the oil to circulate, then shut off for the season to prevent a buildup of moisture. If planning to change the tranny fluid in the coming season, it's also a good idea to do this now for basically the same reason.

2. Increase tire pressures to 50PSI. This will prevent flatspotting and leaks. The tire pressure will drop with ambient temp. Some will say to put the car on blocks, but with modern independent suspension, it's not good to leave it 'unsprung' for long periods. If you want to get really anal, fill the tires with Nitrogen. This is a Dry Gas and will prevent Dry Rot. Nitrogen can be obtained from any welding supply.

3. Store desiccants in the car. These can be purchased and laid on the floor front/back. This prevents mildew from growing and keeps leather from deteriorating due to accumulated moisture. Also, add an open Box of Baking Soda to absorb any odors which may accumulate. The 'Car Cacoons' currently being sold are very good for long term storage and use only a couple bucks electricity the entire season, also reduces door dings and the like. Absent this, use a quality car Cover.

4. Wash the car - don't allow pollution, Tree Sap etc. to work on the paint through the winter.

5. Remove battery from the car and put on a maintainer, preferably inside where it's warm. Be sure to allow plenty of ventilation to prevent Hydrogen Gas buildup.

6. Place the car on a sheet of Vinyl laid out on the garage floor. Make sure the vinyl extends 2 feet from any edge of the car. Garage floors seep moisture through the winter which can condense on the underside of the car, suspension, etc. causing corrosion.

7. Fill Gas Tank with Fresh, Premium fuel. A partial tank will corrode from moist air. Plus, it'll probably be cheaper than filling it next season. Use a stabilizer if you choose, but with Premium Gas, it's usually not necessary. If using a stabilizer, only add it when refueling so it thoroughly mixes with the gas, then run the car home so that the stabilzer can also work it's way through the entire fuel system.

8 Check Anti-freeze to be sure sufficient for temps anticipated.

9. Leave the car out of gear and with the Handbrake Off. If your garage is not level, or you worry about the car being 'rolled', place a brick under the front tire to prevent the car from rolling. Emergency Brake system and Calipers have been known to seize over a season of non-use. If they are engaged, it can be very difficult to dis-engage them (you may need to disassemble the caliper or mechanism to free it). On the other hand, if they are dis-engaged and seize, the hydraulic pressure and/or mechanical advantage of a cable/lever system is often enough to loosen them up again.

10. It may also help to place a couple of Mouse Traps strategically under the car, such as where the exhaust outlet(s), Frame openings, etc. are located. This can prevent something from Moving In to your car over the season. Mice will eat Plastic, Leather and Rubber, in addition to making a mess in general.

[JOHNBMWM5]

Originally Posted by mikey19

so where do I get this "fuel stabilizer"? does the STP branded fuel treatment bottle from walmart count?
or should I look at stores like Autozone or Advanced Auto Parts?

ill already inflated my tires to 35 psi cold, so that shouldn't be a problem.

thanks for the advice!

My tyres are @ 37PSI all round anyway, thats the pressure I drive on.