I am looking to trade my ML350 for a 2015 GL550. About 40k miles for $40k, good shape inside and out, etc.

I know it's relatively similar to my ML but is there anything I need to know in particular about this vehicle? Is the ADS/are the airbags reliable? What about the 4.7 turbo? Anything else?

Oh, and what's the largest tire I could safely fit on the stock AMG rims?

Thanks!

 

Same car, same suspension, engine is bad thought. May be last 100k miles before check engine, may be not.

 

This question has come up 2-3 times in the last couple weeks for 166 V8 vehicles. Have a search around on the 166 sections of the site.

As already stated, good chassis and body platform but sketchy engine near 100k miles and above.

 

Have a ML350 for 5 years and a GLS550 for 8 months. Both bought as CPO.

Different ballgame of maintenance/reliability on the GLS. ML350 has been solid, easy and problem free. Over 100k miles one of most reliable vehicles I’ve owned.

GLS different story. In 6 months of ownership these things were covered under warranty (no doubt at least $10k) on the GLS:

-broken 2nd row AC vent
-3rd row blown rear speaker and grille
-new driver door window switch to eliminate a loud annoying rattle
-entire driver side front wheel axle replaced due to leaking grease from axle boot
-new engine mounts and spark plugs to eliminate shaking while idling
-fixed engine oil leaking on left side camshaft cap on 02 sensor connector and replaced all oxygen sensors
-popping pano roof fixed by re-torquing roof bolts and applied loctite (labor intensive had to remove entire headliner to access bolts)
-left side turbo line leaking coolant fixed drained and filled new coolant and replaced turbo return line
-pin hole size grease leak in passenger side axle boot replaced entire passenger side axle
-front cylinder head covers leaking oil removed air box, intake, cam magnets and cleaned replaced with new seals and gaskets.

And this was a Certified Preowned vehicle with only 41,000 miles “heavily” inspected by Mercedes.

No matter how good of price, DO NOT buy one of these out of factory Mercedes or CPO warranty.

 

Reliability is a concern, especially if you have to pay a shop or the dealer to fix things. I have the 4.7 turbo engine in my 2013, and I have 110k miles on it but have had many little problems the last 25k miles. My air suspension is original and still fine, but I expect to replace the rear air bags any day now. I have a garage and an extra vehicle, so I've fixed most of my problems myself, but it takes a lot of time. It's a wonderful vehicle when it's working, you'll love it! Why are you upgrading from the ML to the GL? Do you need the extra seats or the extra towing? I see you've got a nice collection of Mercedes already, so hopefully you already have a Mercedes scanner and some Mercedes tools. Either buy a good warranty or spend lots of time researching the known problems with the X166 platform and M278 engine. Oil in the engine harness, various electronics issues, turbo coolant lines leaking, etc. If you're buying a 2015, plan on replacing both batteries if they are original. Brakes need replaced often depending how you drive. But the one you're looking at only has 40k miles, it could be good for a long time. Plan on popping the hood often to check for the first signs of coolant and oil leaks, if you catch them early they won't leave you stranded and can be repaired easily. I would recommend doing the second-row headrest modification if you have people riding back there often. Mine burns a little oil so check the oil level every 1000 miles or so.

For tires, do you mean diameter or width? I put a slightly larger diameter tire on my GL, it fits fine and has only rubbed the wheel well liner a tiny bit if I hit a large bump with the wheel fully turned. I also keep them aired up a little higher than the factory recommended value, it helps eliminate some of the wallowing feel that the air suspension has sometimes. I think wider tires look sweet, but I don't know how much they would improve performance. My winter wheels have a different offset than stock, so although the tires aren't wider, they stick out from the wheel well a little bit and I really like how that looks.

 

Hey @JD101b I know what GL you're talking about and wow is a beautiful car, the dealership is just down the road from us and has an excellent reputation, you're in good hands. To ease some of your worries, here is some pricing information from two top tier extended warranty providers, Fidelity and Freedom Warranty, repairs accepted at all Mercedes-Benz dealerships and licensed independents in the country. If you have any questions or would like to see the example contracts that explains coverage from both providers you can reach me at tgibson@highline-autos.com or (855) 924-1333

Freedom Warranty Complete Manufactures Extension:
48 months / up to 100k miles
$0 deductible
-$4,580
$100 deductible
-$4,430

60 months / up to 100k miles
$0 deductible
-$4,745
$100 deductible
-$4,595

Fidelity Platinum:
36 months / additional 36k miles:
$100 deductible
-$6,553
$250 deductible
-$5,790
$500 deductible
-$4,967

48 months / additional 48k miles:
$100 deductible
-$8,553
$250 deductible
-$7,411
$500 deductible
-$6,205