x164 GL 550 vs x166 GL 450
Thread Starter
Member
Joined: Aug 2019
Posts: 173
Likes: 36
2014 GL550; 2010 GL450
x164 GL 550 vs x166 GL 450
I'm in market for another GL having owned and liked my 2010 GL 450 a lot. I'm looking at 2010-2012 GL550 vs 2013-2014 GL 450 with mostly standard options.
For X166 owners who have driven or owned X164 before, any thoughts about the choices above? If I'm looking at X166, any thing or options in particular to consider? X166 GL 550 would be nice but they seem too rare and pricey.
For X166 owners who have driven or owned X164 before, any thoughts about the choices above? If I'm looking at X166, any thing or options in particular to consider? X166 GL 550 would be nice but they seem too rare and pricey.
MBWorld Fanatic!
Joined: Jan 2014
Posts: 1,053
Likes: 355
From: USA - Minnesota
2014 GL350
I'm in market for another GL having owned and liked my 2010 GL 450 a lot. I'm looking at 2010-2012 GL550 vs 2013-2014 GL 450 with mostly standard options.
For X166 owners who have driven or owned X164 before, any thoughts about the choices above? If I'm looking at X166, any thing or options in particular to consider? X166 GL 550 would be nice but they seem too rare and pricey.
For X166 owners who have driven or owned X164 before, any thoughts about the choices above? If I'm looking at X166, any thing or options in particular to consider? X166 GL 550 would be nice but they seem too rare and pricey.
Thread Starter
Member
Joined: Aug 2019
Posts: 173
Likes: 36
2014 GL550; 2010 GL450
Thanks for the interesting note. I try to stay away from turbo regardless of make and model due to complexity and reliability issues (I always DIY). Does the V6 twin has a good track record and easy to work on?
MBWorld Fanatic!
Joined: Jan 2014
Posts: 1,053
Likes: 355
From: USA - Minnesota
2014 GL350
You can find plenty of threads here in the X166 section if you are curious about the issues with the V8. Obviously not everybody has experienced problems, but for those that have, the issues have been severe.
MBWorld Fanatic!
Joined: Aug 2003
Posts: 8,882
Likes: 1,212
From: In my garage
E55, GLS450, GL63, GLE350
The 164 GL550 will be much more reliable. Biggest downfall of the X164 GL550, in my opinion, is the Flava Flav front grill. I recently had to make the choice between the 63, 550, and 450. Given the poor reliability rating of the X166 550, I went with a GLS 450 to replace my X164 GL 450. Love a big V8 but, with the cost of fuel and the poor reliability rating of the bi-turbo v8, the bi-turbo 6 was a no brainer. I still have my X166 GL63 and I love it, but the MPG is beyond terrible.
Last edited by BlownV8; Apr 3, 2022 at 10:11 PM.
Out Of Control!!
Joined: Sep 2018
Posts: 14,666
Likes: 4,568
From: unbegrenzt
2017 GLE350 4MATIC
The 3.0L TT V6 is proving itself to be reliable.
The V8 seems prone to cylinder scuffing, bad valve guides and chain tensioning problems, all fatal or very expensive issues.
Thread Starter
Member
Joined: Aug 2019
Posts: 173
Likes: 36
2014 GL550; 2010 GL450
Wow! Thanks for all your inputs. I thought the X166 V8 was just a carryover from the NA V8 in the X164 550. I didn't realize it's turbo (probably glossed over that) and certainly wasn't aware of the issues listed. It's good to know and thanks.
What about driving experience? I consider my X164 handling to be decent, quiet and smooth, but I hear the X166 is significantly better in handling. I'll try and test drive the X166 but wonder if a short test drive will be that helpful. I know how the Q7 and BMW's X handle (I drive both) and not looking for that kind of handling in the GL. So on the MB smooth comfort scale, how does the X164 compare to the X166 without ABC. One aspect of the X164 V8 I appreciate is how smooth it glides at cruising speed even under acceleration. Is the X166 V6 similar? i.e. it doesn't scream/moan under acceleration?
What about driving experience? I consider my X164 handling to be decent, quiet and smooth, but I hear the X166 is significantly better in handling. I'll try and test drive the X166 but wonder if a short test drive will be that helpful. I know how the Q7 and BMW's X handle (I drive both) and not looking for that kind of handling in the GL. So on the MB smooth comfort scale, how does the X164 compare to the X166 without ABC. One aspect of the X164 V8 I appreciate is how smooth it glides at cruising speed even under acceleration. Is the X166 V6 similar? i.e. it doesn't scream/moan under acceleration?
Trending Topics
Member
Joined: Jun 2018
Posts: 150
Likes: 23
2017 GLS450, 2013 GL450, RIP 2011 GL450 (totalled)
I've had both, and my x166 has been far more reliable than the x164. I am nearing 130k on original air struts, which would defy science on an x164.
Engine-wise, my x164 had intake flap problem. Other problems were groaning power steering with likely forthcoming leak from plastic reservoir, and host of water issues that was not related to car but a shoddy windshield job (although I believe water in SAM is somewhat common as its lower point in car and the x164's have leak problems).
Overall, the x166 feels better built/better materials all around with the exception of the driver seat wear. As others noted, the M278 is a bit of a minefield compared to overall bulletproof M273. I'd steer clear of 2014 models and check the engine serial number against the bulletin. Mine is a 2013 and seemingly out of the danger-zone for valve/piston/cylinder wall failure.
I felt the x164 was a bit softer in town over bumps, but both have the 'narcotic' highway smoothness. I miss the hydraulic steering feel on x164, but the electric steering is a more reliable system overall in the x166; and l feel that the x166 handles better.
Engine-wise, my x164 had intake flap problem. Other problems were groaning power steering with likely forthcoming leak from plastic reservoir, and host of water issues that was not related to car but a shoddy windshield job (although I believe water in SAM is somewhat common as its lower point in car and the x164's have leak problems).
Overall, the x166 feels better built/better materials all around with the exception of the driver seat wear. As others noted, the M278 is a bit of a minefield compared to overall bulletproof M273. I'd steer clear of 2014 models and check the engine serial number against the bulletin. Mine is a 2013 and seemingly out of the danger-zone for valve/piston/cylinder wall failure.
I felt the x164 was a bit softer in town over bumps, but both have the 'narcotic' highway smoothness. I miss the hydraulic steering feel on x164, but the electric steering is a more reliable system overall in the x166; and l feel that the x166 handles better.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Member
Joined: Aug 2019
Posts: 173
Likes: 36
2014 GL550; 2010 GL450
Thanks. It looks like I may settle for X164 550 for now and save up for 2015+ X166 later (or wait a few years for more depreciation). I had to fix the tumbler flap in my GL 450 too with new intake manifold and a few more things. As long as it's not an engine or transmission overhaul or super expensive parts I should be OK.
Does the V8 in the 2013-2014 X166 GL 550 also has the same cylinder scoring/failure issues that the detuned X166 V8 in the GL 450 has?
Does the V8 in the 2013-2014 X166 GL 550 also has the same cylinder scoring/failure issues that the detuned X166 V8 in the GL 450 has?
Member
Joined: Jun 2018
Posts: 150
Likes: 23
2017 GLS450, 2013 GL450, RIP 2011 GL450 (totalled)
Yes, some may even argue more so with the 550 given the additional boost. Vehicles in colder climates may be more prone to cylinder lining damage with the startup friction wear.
Transmissions in the x166 are bulletproof, transfer-case chain stretch can happen in both x164 and x166 (think its the same unit) but is an easy fix if caught early.
x164 550's are a nice looking machine, keep us updated!
Transmissions in the x166 are bulletproof, transfer-case chain stretch can happen in both x164 and x166 (think its the same unit) but is an easy fix if caught early.
x164 550's are a nice looking machine, keep us updated!
Member
Joined: Feb 2020
Posts: 126
Likes: 58
From: Gresham, OR
GL450
"and save up for 2015+ X166 later (or wait a few years for more depreciation)"
Used cars aren't depreciating any more. I mean, they depreciate if you drive them a lot of miles or damage them, but a 2015+ X166 is worth MORE today than it was at the same time last year, and the projections I've read say that they won't depreciate over the next 12 months. The supply and demand equation is all messed up and the auto industry won't be able to catch up for a long time. Go ahead with your x164 plan, and save up for a good x166. But don't count on depreciation helping you in the short term, and maybe not in the mid term.
Used cars aren't depreciating any more. I mean, they depreciate if you drive them a lot of miles or damage them, but a 2015+ X166 is worth MORE today than it was at the same time last year, and the projections I've read say that they won't depreciate over the next 12 months. The supply and demand equation is all messed up and the auto industry won't be able to catch up for a long time. Go ahead with your x164 plan, and save up for a good x166. But don't count on depreciation helping you in the short term, and maybe not in the mid term.
Out Of Control!!
Joined: Sep 2018
Posts: 14,666
Likes: 4,568
From: unbegrenzt
2017 GLE350 4MATIC
2019 GLS450 is the best preowned (and when new) MB available imo.
Thread Starter
Member
Joined: Aug 2019
Posts: 173
Likes: 36
2014 GL550; 2010 GL450
After much contemplation and taking into account everything I've learned about the X166 and M278, I've taken delivery of a well-equipped 2014 GL550. I got it quite cheap due to an "engine problem." It has all the options I care about including exterior color and Designo interior. The only major missing option for me is the active curve system which proved to be elusive during my search for this project car (I wonder what it will take to retrofit this).
I've already started my diagnostics and as expected the cylinders are scored (I'll share some photos later). I'm not sure yet if this is the cause of the engine knocking noise. My philosophy going in was why pay more a for seemingly running car when it will very likely develop cylinder scoring sooner or later; I'd rather get something for an engine rebuild project which is what I'm planning to do now (i.e. re-sleeve the bores). There are some relatively minor issues I will address as well. I look forward to sharing my restoration journey on this forum. Wish me well...
BTW: One a couple of X166 GLs I recently fixed for others (one with camshaft replacement due to misaligned tone ring and the other needed some fuel injectors), both showed cylinder scoring/scuffing but after camshaft/injector replacements both drove fine. So, I believe there are lot more M278 GL's out there with scuffed cylinders that drive fine. I've also noticed that in these GLs, including mine, the wall scuffing doesn't necessarily affect compression (unlike a BMW N63 with low compression which I traced to scored cylinders).
I've already started my diagnostics and as expected the cylinders are scored (I'll share some photos later). I'm not sure yet if this is the cause of the engine knocking noise. My philosophy going in was why pay more a for seemingly running car when it will very likely develop cylinder scoring sooner or later; I'd rather get something for an engine rebuild project which is what I'm planning to do now (i.e. re-sleeve the bores). There are some relatively minor issues I will address as well. I look forward to sharing my restoration journey on this forum. Wish me well...
BTW: One a couple of X166 GLs I recently fixed for others (one with camshaft replacement due to misaligned tone ring and the other needed some fuel injectors), both showed cylinder scoring/scuffing but after camshaft/injector replacements both drove fine. So, I believe there are lot more M278 GL's out there with scuffed cylinders that drive fine. I've also noticed that in these GLs, including mine, the wall scuffing doesn't necessarily affect compression (unlike a BMW N63 with low compression which I traced to scored cylinders).
Member
Joined: Feb 2020
Posts: 126
Likes: 58
From: Gresham, OR
GL450
Miles and Price?
Thread Starter
Member
Joined: Aug 2019
Posts: 173
Likes: 36
2014 GL550; 2010 GL450
If you have the skills to re-bore the cylinders, then I think a cheap 2014 GL550 would be an excellent vehicle to put the time and effort into. Can you give us a little more info about the vehicle, in order for us to understand your decision? Miles and purchase price? Or do you want to keep the purchase price as private information, to help with your negotiations when you sell it?
Member
Joined: Feb 2020
Posts: 126
Likes: 58
From: Gresham, OR
GL450
It has 130k mile and got it for 10k . . . plus a few hundred bucks to transport it from out-of-state. Besides engine, it needs some TLC - new tires, radiator, and front bumper lower molding as well retouch of a few scratches. After this I'll be on to the unnecessary but desired - upgraded head unit, refinish rims to remove curb rash, some interior/exterior cosmetic accessories, etc.
Thread Starter
Member
Joined: Aug 2019
Posts: 173
Likes: 36
2014 GL550; 2010 GL450
For the X166 GL/GLS 550, only the V8 is available. The V6 in the GL450 came out in MY 2015 so if you don't want to deal with the potential hassle, then the V6 is the way to go. Compared to my well-optioned X164 GL450, most of the standard options X166 GL450 I found didn't tip the scale for me.
