Panama

We may leave our SL in storage in the garage for about 5 months. This is dependent on Covid and whether we continue our plans for the winter.

I am asking experts here sbout this just to get prepared for the storage of the vehicle and any peculiarities with the SL. IF you were leaving your SL in storage for a while, what cautions would you take?? Anything you can think of would be appreciated. I am going to use this to make a checklist. I have read about battery trickle chargers and one that MB offers and the battery situation with the SL which is a little odd to my experience with other cars.

Any real life experiences or suggestions in a "storage for SL dummies" format would be great. I am still learning about this car and where things are and how they work...thanks.

threeMBs

I do not think there's anything special about SL storage vs. any other car: full tank of quality gas with proper amount of Stabil (1oz/2.5g, or about 8ozs per SL tank), set tire pressure to max on tires' sidewall (most SL OEM tires are 50psi), ideally put a lot of padding under tires to resist flat spotting, trickle charger (or disconnect battery if unable to trickle charge) and indoor car cover.

tx170754

I have done this ( and still doing it ) on both my CL and SL for the last couple of years, just put a trickle charger on the main batteries, no problems whatsoever. I’m starting the cars once in a while but that is about it.

Dr. Manhattan

I bought my '17 450 at the end of May this year. Circumstances separated me from it for a couple of months, so it ended up sitting in the garage with a CTek charger connected to the "jump" terminals under the hood. When I returned, it was perfectly fine...though the new set of factory-type runflats had definitely flat-spotted. That went away fairly quickly on the first drive, though. You'll be fine with an AGM-rated trickle charger on the main battery. As to the aux battery (also AGM), it's not connected to the car when the car is shut off. That is, there are no loads drawing on it...unlike the main battery. If your auxiliary battery is in good condition, it'll probably be fine in storage too, even without charging...for the seasonal situation that you're describing.

When gasoline is sitting in a full, sealed container or system (like the SL's tank), it stays fresh a lot longer than some people think. One of my Corvettes ended up sitting for four years once with a full tank of untreated gas in it. This was a modern car with injection and a sealed tank (no vent in the gas cap). It started right up and ran perfectly. The engine in my '17 Chevy Volt virtually never runs. It still has some of the four-year-old delivery gas in its tank, but Chevy designed its fuel system knowing this could occur, so they run the tank under a slight positive pressure which keeps the gas viable far longer by preventing the aromatic elements in the fuel from evaporating. It's only when the gas is in an unsealed system (vented gas cap, etc.) that you run into problems due to evaporation of these fuel elements. Once this occurs, what you have left is something less than gasoline and not only can it be difficult to combust properly, components left in the fuel can turn to a varnish-like substance that can plug injectors, etc.

I'm not saying your gasoline will last forever by any stretch...just that for a matter of half a year or something on that order, treating your gas is just a "piece of mind" thing. Another thing to consider is that there may be a potential issue with mixing treatment additives and our SL's D.I. system. Some manufacturers are quite finicky about adding anything to your fuel, and I honestly don't know how M-B feels about it in our cars. Consequently, while I do treat all of the fuel for my lawn equipment, I don't treat my vehicle fuel, and have not had any problems. If I was looking at really long-term storage, I would probably just drain the system, but that's just me. Obviously, do whatever gives you piece of mind...

threeMBs

About 12 years ago when my 2003 SL550 with under 3K miles at the time with 1/4 tank of gas was sitting without being started/driven for four-five months, both my fuel filter and fuel pump went bad. The cost was about $1,200+. Since then, I always put 4oz (1oz/5gal) when I refill my 2015 SL. The car is not stored but sometimes not driven for a couple of weeks. A piece of mind, not to mention a huge headache and costs associated with it, worth a few pennies. If a car is actually "stored", it is a no brainer to use a stabilizer.

tx170754

Had my SL 500 in the storage every winter for like 5 months in the last 10 years or so and never put anything in the tank, again started it periodically never had any problem.

.LMS.

For mine last year: gas stabilizer, trickle charger. That's it. Started up first try after 5 months, and I didn't notice any flat spots in the RF tires. Maybe you don't really need the gas stabilizer, but it's cheap so why not.

Panama

Thank everybody for taking their time to reply.

One reason I asked about this was I remembered reading about possible problems with the second battery and maybe causing vehicle problems. I remember reading about it but could not find it anywhere and maybe I missed it or looked in the wrong section but I could not find info about long term storage and this second battery. I never had a car with a second battery.

I was planning on putting treatment in the fuel. The blue stuff I think called Startron has been good for my boats.

I appreciate the help... That second battery thing is a learning curve for me.

Ridamo

You can always leave it with me in S FL. I would be glad to drive it regularly to keep the battery charged 🌴😄😄😄😁

bobpun

Panama, To prevent flat spots on the tires after long-term storage I drive my SL onto 2' x 3' 1 1/2" thick styrofoam board and increase the air pressure in the tires. Since I stared using the styrofoam I have never experienced tire flat spots.

.LMS.

Clever solution.

Panama

VERY GOOD SUGGESTION...Great idea. Thanks for taking the time to inform us as to how it worked.

Keon

Ideally, you should also treat all seals before storage as well. Also, start up the car if you can sometimes and let it run for a bit. Operate the hardtop and raise/lower your hydraulic suspension, too.

rmorin49

Many argue that starting the car does more harm than good unless you actually drive it to get it up to full operating temperatures. Just idling in the garage is not the best thing to do. If you have it connected to a good battery maintainer it is best to just leave it alone.

Panama

THANK YOU....
I picked up some good ideas and tips. Thanks to everyone for taking the time to reply.

Dr. Manhattan

Yes, but you'll notice that I specified a full, sealed tank/system. When the tank is full, there's practically no space for the fuel to evaporate into. 3/4 of your tank was empty air space, which by itself would allow some evaporation to occur...though I'm still surprised that you had that much trouble. Since my last post above, I've checked my owner's manual, and M-B says fuel preservatives (Stabil, etc.) and fuel system cleaners (Gummout, etc.) are permissible after all. Personally, I've never had a problem using untreated top-tier gas in a full tank, but if you feel the need to add stuff, go nuts...



Exactly! As to starting the car occasionally "and running it for a bit"...don't, unless you're prepared to run it long enough for the oil to reach full operating temperature. Running it just until the coolant warms up will leave a lot of condensation in the oil which can turn into all manner of nasty s#&* that you do not want sitting inside your engine long-term. The oil has to get really good and warm for some period of time in order to steam all the condensation out of it. It may seem counter-intuitive, but it's actually better to not run the car at all, unless you're prepared to run it quite a long while...and mind you, just idling the engine in winter temps will probably never get the oil hot enough to steam the condensation out of it. That will require actually driving the car a while...which, if you live in the salt belt, is not very desirable. In that situation, it's probably best to let that sleeping dog lie.

visionatsea

One other suggestion---change oil just before storage.

rmorin49

If the garage is not 100% "critter proof" you should consider some type of preventive agents. Some swear by mothballs or other chemicals that can be placed in the engine bay or around the car to deter rodents. If you are certain rodents are not an issue ignore this post but be advised mice and other rodents can do a lot of damage, mainly to wiring.