Does anyone have any real experience between the 580 and 450? Any pluses and minuses beside engine power, smoothness, etc. Am specifically interested in reliability and engine performance in general as a family hauler.

Additional context: Again, my BMW dealer is offering me same amount we paid for our X7 in exchange to some issues they've been trying to fix since we got it brand new not long time ago this year (their way to avoid buyback, which I appreciate). They have many X7s (none of them is as good as ours) but they also have 3 good and well equipped GLS (2x 450 and one 580). I am tempted, but still not sure. X7 issues will be fixed soon for sure but can take sometime, and I don't mind the GLS but still LOVE the X7. If I decide to trade for a GLS, am interested to hear about the 450 vs 580 outside the typical engine power discussion.

 

Your statement contradicts itself. You ask if there are differences besides the engine, then you ask about reliability and engine performance.

The 450 isn't slow, but the 580 moves effortlessly. The M176/177/178 engine has been in use for years in various vehicles. I don't believe there are any major known issues.
Outside the engine, the 580 lets you add E-ABC and includes some optional things on the 450 as standard.

 

If the 580 has E-ABC, I'd get that. I have a GLE 580 with E-ABC and 22" wheels and at the moment I'm renting a GLS 450 with airmatic and 21" wheels. The I6 is adequate even with 7 people going up very steep grades, sure you can hear the engine straining under those extreme circumstances but it's a lot better with the MPGs than the V8. I'll say that I easily got used to the I6 after a 100km of driving, and I can't believe I'm saying this but I probably wouldn't even miss the V8, afterall it's a family hauler and not a sports car.

What I miss about my GLE is the E-ABC. I don't feel any connection to the road with the Airmatic, sport mode is hardly discernable from comfort mode. I don't feel as confident taking curvy roads as fast as I do in my GLE since the E-ABC also acts as sway bars keeping the vehicle flat in turns. I have also learned that the electric 2nd row seats are really slow to move out of the way for the 3rd row passengers to enter/exit. My only comparison would be Escalades and Suburbans rentals, I much prefer the manual 2nd row folding operation in those vehicles to make it faster.

 

I didn't know this but I read that the GLS (including the GL) has always been designed for more comfort than the GLE (and ML) so maybe my comment here is a bit of an apples to oranges comparison.

 

Our E-ABC GLS feels very connected to the road. It's actually deceptive and can get you into trouble since it won't feel like your on the edge until the tires break free.

 

We got the 8 as the 6 did NOT qualify for the Fed Tax (company car) deal....due to weight. That said, it has been a blessing to have power on tap, ZERO issues with the engine, certainly as compared to the M157 in my E63. The Designo interior is amazing....(I think you can get that on the six). On the rate times we have needed a "truck" (towing)...it is a god send. Now we have a Sprinter 3500 (dualie) that we use to tow the occasional trailer - did so just yesterday picking up a new medical bed.

 

M17x 4.0TTV8 is becoming more frequently known for rear main seal failures as a result of failed oil-vapor separators. Most commonly in E63 installations but also reported elsewhere. A few recent incidents reported on mbworld. Oil-vapor separator design is borderline and seems sensitive to tube/pipe geometry of each vehicle installation. It is more or less a distillation system and sludge builds in the still (OVS) and internal valves, depending on vapor temperature and flow velocity which is vehicle installation dependent.

Read this site.

Do not own any MB without manufacturer’s warranty.

Caveat emptor in extremis.

 

Have you read or heard of any examples of the RMS on the GLE or GLS? I haven't yet. 🤞🏽

 

No.

A question for you: have you read all of the RMS failure posts on this site?

 

Not all the posts since that RMS thread is quite long but I started following it maybe a year ago. Hence the crossing of fingers, I'm hoping that the RMS issue isn't contagious across all the models, and so far it doesn't seem to be but maybe I missed something that you might be aware of?

 

The only engine that I know of where this was common, is the Cummins inline 6 in the years just prior to their adopting DEF.

Even in that case it's not enough to reduce its desirability.

 

I thought the tires would unexpectedly break free in curve mode but I got a progressive understeer the one time I went 9/10ths in a corner.

 

If you love the x7, I don't think that you will like the 450. The 580 (with E-ABC) is much more connected to the road and enjoyable to drive if you want a feeling like the x7. It is not on the same level of driving feel as the x7 though.

The 580 (with E-ABC) does give a superior and smoother ride for its passengers than the x7.

Does the dealer's 580 have any other options like executive rear seats or captain's chairs? Acoustic glass? Off-road package? AMG line?

 

To be eligible for the Section 179 deduction, a vehicle must have a GVWR (gross vehicle weight rating) over 6,000 pounds, but not more than 14,000 pounds. The GLS 450 qualifies for Section 179. It weighs 7275lbs GVWR.

It doesn't really matter since you already have your V8 but I thought others should be aware.

 

I know a person who's 450 didn't qualify. Its also not on "the list". Maybe he had a worthless accountant?

 

Thanks everyone, I appreciate the feedback. I've already settled on a GLS last night and it's officially home in my garage.

I have been reading online dozens of threads on this website and other forums/platforms, and given some issues that slightly impacted my personal experience with the V8 engine coupled to the 9G transmission, we as a family decided that we do NOT want the V8 engine specifically on a GLS. I appreciate what Chassis posted above but It wasn't my main concern nor that i found many info about it, but I'll take as another hypothesis or potential issue that I don't need to even think about now. My original thread here was just around the day I decided that this is what I wanted, but I thought I'd give it one last chance and ask myself, which didn't change my opinion. I test drove a few 580s and 450s and it just made it easier to decide; Unlike how it feels weird (though still smooth) in the W222 and W223, the inline 6 cylinder in the GLS actually drove VERY smooth, pulled really well, and eliminated any vibrations at idle as well as rough up/down shifting. This was consistent among all GLS SUVs I tested (8 in total, 5 + 3). Coming from BMW, the engine and shifting smoothness was the #1 priority as a family multi-hour highway trips SUV. Hence, I strictly shopped the 450, and wanted a fairly equipped one

Thanks again everyone. Am vert excited about our GLS. I will post about it in a separate thread on this sub-forum very soon as I get to drive it more and learn more about it.

 

We've talked about this before, there is no "list", and he had a terrible accountant. ANY MPV with a GVWR over 6k lbs qualifies, on a list or not. Just can't be a sedan, coupe, passenger car etc. SUV, minivan, pickup...all qualify.

 

Are you sure about sedans? I know two people who have Taycans under the full deductions of section 179.

 

Yeah, I'm sure. A lot of accountants will do it with a sedan but the IRS specifically requires it be a multipurpose vehicle. My accountant offered to do it with the S Class which is also over 6,000 lbs GVWR but I chose not to take the risk and to lease it as I always do. The accountants argument was the IRS is not looking at that level of detail.

 

I see. Thanks!

 

RE the 179 deduction…. This is also available for sedans used in a trade or business.

The 179 deduction is capped for vehicles, with different limits (adjusted for inflation) based on weight. For vehicles placed in service in 2023, the deduction for passenger vehicles with GVW under 6,000 was $12,200 (Section 280F also comes into play re the depreciation deduction for passenger vehicles under 6,000 GVW). For vehicles with GVW between 6,000 and 14,000, the limit was $28,900. There is also a separate classification of Other (ambulance, delivery van, etc.) for which there is no 179 limit. I don’t find the term “multipurpose” in the code.

But to Steve's point, the IRS does not publish a list of vehicles that qualify for the higher limit. Various organizations publish a list, but they are not the IRS. The IRS sets the qualifying parameters and it is up to the taxpayer to determine qualification.

 

They never are....until they are...............

 

Thats why I didn’t risk it with the sedan, but there is no risk with a utility vehicle over 6,000 lbs GVWR.

 

The RMS issue due to bad OVS' is on the LS2 version of the m17x engine. I do not believe the issue has appeared on the m176. Additionally, both the part numbers for the OVS' and the RMS have been updated and those changes should be in the newer models.

 

Until we all move to EV, am pretty sure that every engine and any variant we choose will end up developing some form of a VERY common issues down the road. Newer engine variants surely have some issues that will get to know later on. I can only name a few engines that I know that haven’t developed any common issues at all…
The 4.3L 3UZ-FE engine in the 2000+ Lexus LS430 is the first one I could name. Am not sure I could name a single Mbenz engine but others are welcome to correct me. The newer inline-6 seems to be solid so far…