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I would not defer or neglect any critical fluid change, including the transmission. Iridium plugs at 50,000 miles is a bit ridiculous since they should be good for 100,000 miles, but not a transmission service at 70,000 or 75,000 miles. Also, engine oil should be changed every 3000 to 5000 miles -- 10,000 miles is nonsensical marketing hype.
Great point about the spark plugs. In my view, changing them at 50K miles is absolutely a waste of money and I have no doubt about that. I know nobody races his GLS to gain back 0.01 seconds or few horse powers. Those sparks are good for 100K miles and at 50K replacing them isn't required at all (not to mention the cost of doing so!)
I am planning to go to my independent shop for an oil change. He was a MB master mechanic and lights up when he gets to work on them. I can get it back faster if I bring him the parts. What oil do you use for a GLS 580 ? He always insists and recommends OEM filters. He says why take a chance on giving a dealer a reason to deny any future claims if you use OEM.
Great point about the spark plugs. In my view, changing them at 50K miles is absolutely a waste of money and I have no doubt about that. I know nobody races his GLS to gain back 0.01 seconds or few horse powers. Those sparks are good for 100K miles and at 50K replacing them isn't required at all (not to mention the cost of doing so!)
I have been told by two service departments that the reason for changing the plug is at 50,000. It's not because they wear out, but because they can seize in their holes.
If you've ever dealt with that, you do not want to deal with it again.
If you want your warranty/service contract to stay in effect, maintenance schedules are important.
Just have the plugs done by an independent, its not expensive. My independent charged me $550 on my S560, and they found the valve cover leak in time for it to be covered under warranty!
I have been told by two service departments that the reason for changing the plug is at 50,000. It's not because they wear out, but because they can seize in their holes.
If you've ever dealt with that, you do not want to deal with it again.
If you want your warranty/service contract to stay in effect, maintenance schedules are important.
I see... but yeah, I would love for the next owner of my GLS to enjoy the car, but since the 1st owner (for example me) will not keep it until 100K miles, why do I, or we, need to worry about paying for that, so that the 2nd owner or his warranty won't have to pay for a seize spark plugs which is primarily then a Mbenz design issue? That's just my point. If am keeping it until 100K when the plugs truly need to be replacement based on the plug manufacturer, then I'd do that.
Having said that, if someone offers me $500 to replace them, as in the post above, I'd probably do that early just for spiritual reasons . But for thousands of dollars? No way am wasting my money on that. That's just way too much for something the car does not need and will never ever need during my max 70-75K miles for an SUV ownership as far as mileage.
Personally I enjoy maintaining my cars, so even though I'm not likely to keep it I still want to have done what needs to be done. I waste $500 on sillier stuff lol
Personally I enjoy maintaining my cars, so even though I'm not likely to keep it I still want to have done what needs to be done. I waste $500 on sillier stuff lol
That's my point.. and I added this to my post too " if someone offers me $500 to replace them, as in the post above, I'd probably do that early just for spiritual reasons . But for thousands of dollars? No way am wasting my money on that. That's just way too much for something the car does not need and will never ever need during my max 70-75K miles for an SUV ownership as far as mileage"
But it's not worth the spiritual aspect at 1500-2000 USD. I do waste more than couple hundred dollars on "silly" car related stuff, but sparks for 1500-2000 USD isn't something that will bring joy to me and I won't even notice the difference.
But that’s just it, you don’t have to spend thousands of dollars. I had it done for $550 by an MB specialist. Your GLS would be cheaper because it’s two fewer plugs. I’d much rather have the work done by an independent vs not do it at all. Scheduled maintenance I have done at MB because it’s easy and it’s not that much more expensive, but anything big the dealer is way too expensive. Plugs, brakes, any kind of repairs or suspension issues that aren’t under warranty the dealer is thousands of dollars wasted.
In my case it also found the valve cover leak. Had that not happened I might have kept that car in which case that would have eventually cost me $5,000+ because the car would have been out of warranty by the time I realized it was leaking. Doing the scheduled maintenance uncovers repairs that need to be done before they grow to be big problems that cost even more to fix.
But that’s just it, you don’t have to spend thousands of dollars. I had it done for $550 by an MB specialist. Your GLS would be cheaper because it’s two fewer plugs. I’d much rather have the work done by an independent vs not do it at all. Scheduled maintenance I have done at MB because it’s easy and it’s not that much more expensive, but anything big the dealer is way too expensive. Plugs, brakes, any kind of repairs or suspension issues that aren’t under warranty the dealer is thousands of dollars wasted.
In my case it also found the valve cover leak. Had that not happened I might have kept that car in which case that would have eventually cost me $5,000+ because the car would have been out of warranty by the time I realized it was leaking. Doing the scheduled maintenance uncovers repairs that need to be done before they grow to be big problems that cost even more to fix.
GLS has very common wiring harness issues when the harness is removed after a few years on the road (a number of reports about it here for the GLS/GLE). That's my main concern about having an independent shop do the spark plug replacement, even for $500. If Mercedes does the work, any wiring harness issues along the way will likely be covered under warranty. However, if an independent shop attempts to remove the harness and it fails apart on him, I don't believe my Mercedes warranty would cover it. I can still consider it and will ask my mechanic to inspect the wiring harness carefully before he touches it. I was already planning on getting the extra oil change at 5K mile intervals done at my local mechanic, while keeping the 10K mile intervals at the dealer.
I am planning to go to my independent shop for an oil change. He was a MB master mechanic and lights up when he gets to work on them. I can get it back faster if I bring him the parts. What oil do you use for a GLS 580 ? He always insists and recommends OEM filters. He says why take a chance on giving a dealer a reason to deny any future claims if you use OEM.
I use Pennzoil Platinum Euro Full Synthetic 5W-40. Made from natural gas (whatever that means), API SP rated and MB 229.5 approved. Your mechanic is correct about using Genuine or OE (not OEM) filters. Check FCP OE Academy to understand the difference.
For my engine (M276) the OE filter is Purflux 2761800009 and identical to the Mercedes Genuine filter.
I have been told by two service departments that the reason for changing the plug is at 50,000. It's not because they wear out, but because they can seize in their holes.
If you've ever dealt with that, you do not want to deal with it again.
If you want your warranty/service contract to stay in effect, maintenance schedules are important.
I’ve heard that reason given before, but remain doubtful. Interesting that my maintenance manual says to change the spark plugs at 46,500 miles.
GLS has very common wiring harness issues when the harness is removed after a few years on the road (a number of reports about it here for the GLS/GLE). That's my main concern about having an independent shop do the spark plug replacement, even for $500. If Mercedes does the work, any wiring harness issues along the way will likely be covered under warranty. However, if an independent shop attempts to remove the harness and it fails apart on him, I don't believe my Mercedes warranty would cover it. I can still consider it and will ask my mechanic to inspect the wiring harness carefully before he touches it. I was already planning on getting the extra oil change at 5K mile intervals done at my local mechanic, while keeping the 10K mile intervals at the dealer.
If you find a very well regarded independent shop with MB trained techs and a great reputation like the shop I used that’s not really a concern. I have no concerns about that independent mechanic owning up to anything they might cause when doing work.
What does your dealer charge for just an oil change? I was surprised mine was only $160. So I just have the 5k extra changes done there too
If you find a very well regarded independent shop with MB trained techs and a great reputation like the shop I used that’s not really a concern. I have no concerns about that independent mechanic owning up to anything they might cause when doing work.
What does your dealer charge for just an oil change? I was surprised mine was only $160. So I just have the 5k extra changes done there too
I just checked my Service A visit in July, and I paid $279 for everything including the multi-point inspection with video + loaner until next morning. Of course, I decline some of the add-ons like wipers, batteries, fuel additive, etc. Not too bad. Other dealers would have charged me 400-700 USD though, but these guys have no BS service other than the optional add-ons. My BMW dealership would have been a standard 150 USD at the dealer regardless of the engine size, or 120 USD if I buy 2 years of annual service in advance, not counting brake fluid every 2 years, likely lower than other indy shops around.
Yeah thats great, well worth it for the ease and the loaner.
My independent also has loaners, they're VW Jettas but its nice to have a loaner. I do like driving a different MB for a day or so while its in for service...so thats worth something to me too.
BUT, dealer was $1,800 for plugs vs $550 at the independent. Dealer was $2,500 just for brake pads while the independent was $2,100 for pads AND rotors, and I was able to use ceramic pads which the dealer refused to do. The rotors alone are $1,000. That savings is worth using him vs the dealer.
I just checked my Service A visit in July, and I paid $279 for everything...
Sorry if you have stated this before, but what car and engine did you have serviced? 5W-30 seems a little "light", especially if you have a turbo engine. I would want 0W-40 or 5W-40 API SP rated and MB 229.5* approved oil. I've never heard of Mercedes Benz GEO oil.
Anyway, just make sure the oil is appropriate. You can find the specifications for your engine here:
My MB Dealer for Service B did this.
They fitted 0w-20 oil and didnt change the brake fluid.
Its the first service B with 18,500 kilometers on the clock.
My MB Dealer for Service B did this.
They fitted 0w-20 oil and didnt change the brake fluid.
Its the first service B with 18,500 kilometers on the clock.
I hope they were using MB 229.71 or MB 229.72 approved oil as 0W-20 is not listed with any other MB spec. Go to the link I provided above.
Still, I would never use a 0W-20 weight oil in a Mercedes turbo engine, especially living in a tropical climate. But, that's just me.
That 89.5 USD is the labor part of it for the X167 engine.
Originally Posted by GTIBlack
Sorry if you have stated this before, but what car and engine did you have serviced? 5W-30 seems a little "light", especially if you have a turbo engine. I would want 0W-40 or 5W-40 API SP rated and MB 229.5* approved oil. I've never heard of Mercedes Benz GEO oil.
Anyway, just make sure the oil is appropriate. You can find the specifications for your engine here:
X167 inline-6 is NOT MB 229.5 and this should not be used in the X167 450 (not even for the 580).X167 in-line 6 must use MB 229.51 (or other options below). They are two different specs.
MBenz GEO 5W30 is the MB-Approval 229.52 specification in a 5W-30 viscosity. Looks like they put the right oil. In fact, 0W-40 or 5W-40 that u suggested are very rare for 229.51 modern applications, and even if they are acceptable, Mbenz X167 manual clearly says that it is recommended to use ("lowest SAE viscosity class in each case"). Hence 5W-30 is the best option for the engine in this case for MB 229.51 specs. 0W-40 or 5W-40 are recommended for the GLS 600 but not mentioned for the 450.
Another acceptable option is 0W-20 but only for the 229.72 specification case (but I would only go this route if I live somewhere dominated by 12 months of cold months). 229.51 with 5W-30 has the best balance and well within what the X167 manual recommends.
I can't find my work order right now, but Mercedes changed oil recommendations based on new LSPI concerns.
My shop used the new spec when they changed my AMG53 oil in July '25.
The new spec made many of the old charts obsolete. Mine went from the previous "5WXX" to "0WXX."
I can't find my work order right now, but Mercedes changed oil recommendations based on new LSPI concerns.
My shop used the new spec when they changed my AMG53 oil in July '25.
The new spec made many of the old charts obsolete. Mine went from the previous "5WXX" to "0WXX."
Yes, this is why in my post above I was against 0W-40 or 5W-40. I would not go that route no matter what. Also, LSPI is that reason Mercedes has stopped recommending MB 229.5 for its newer 4-cylinder and Inline-6 turbo engines. MB 229.51 is the one recommended now because of LSPI among other options depending on the engine. These newer ones like MB 229.51 and 229.72 all have LSPI-resistant chemical formulas. The recommended viscosity for each should not change. If you go with 229.51 simply take 5W-30, and if u go with 229.72 then 0W-20 is the best option.
Most dealers/techs would go with 0W-20 229.72 cause it is always safe and matches what the manual clearly recommends the thinnest oil that is still within the acceptable specs. If u don't want to be on either extremes (which is my strategy), 229.51 with 5W-30 has the nice balance for those who live in a mixed weather with a few months of warm weather combined with cold months. it is not the absolute thinnest and not the thickest approved oil option for this engine. Both of these are post LSPI dilema and are LSPI-proof
Good info about the newer engines. WRT LSPI, API SP or above is the new formulation to address LSPI risks. Of course, Mercedes may have their own approval code for similar formulations.
I do wonder what is the motivation to move to a 0W-20 oil. We know it should improve gas mileage, etc., but is it good for our engines? Just because it is recommended or specified does not mean it is necessarily the best choice for our engines. There are manufacturers in the US (i.e., GM) that are backing away from 0W-20 due to a higher number of catastrophic engine failures and are now recommending 5W-30. The craziness with low viscosity oils appears to be driven by politics rather than good engineering.
HOWEVER, staying with the recommended viscosities while under warranty is probably prudent, especially if you stay with genuine/OE oil filters and shorter change intervals. My cars are no longer under warranty, so I don't need to worry about that.
WRT LSPI, API SP or above is the new formulation to address LSPI risks. Of course, Mercedes may have their own approval code for similar formulations.
One example is the MB (229.51). It is the new designation they use for LSPI (instead of the old MB 229.5).
Originally Posted by GTIBlack
I do wonder what is the motivation to move to a 0W-20 oil. We know it should improve gas mileage, etc., but is it good for our engines? Just because it is recommended or specified does not mean it is necessarily the best choice for our engines. There are manufacturers in the US (i.e., GM) that are backing away from 0W-20 due to a higher number of catastrophic engine failures and are now recommending 5W-30. The craziness with low viscosity oils appears to be driven by politics rather than good engineering.
HOWEVER, staying with the recommended viscosities while under warranty is probably prudent, especially if you stay with genuine/OE oil filters and shorter change intervals. My cars are no longer under warranty, so I don't need to worry about that.
I agree. This is similar to tire PSI. Manufacturers push for the maximum allowed/safe limit to inflate claimed MPG (especially EVs or V8 ICE cars, it gets crazy and not comfy at all at the recommended limit!). The same applies to oil.. better MPG is achieved with the thinnest allowable oil viscosity. That's why I sometimes run my tires 3-4 PSI lower than recommended (to get the best comfort level possible without damaging the tire), and also prefer an engine oil viscosity that isn't the absolute thinnest or thickest. The 5W-30 is in the sweet spot within the recommended range, not the thinnest allowable oil prioritizing fuel efficiency over wear, and not the thickest either. I still think 5W-40 is out of range though.
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