2016 MB GL450 116.3k mi; HPL Supercar 5w-40, 10.2k mi

[Panda87]

Nice report!

You're right about the Mercedes spec being very robust. I have two cars with this engine (M276.8) and have routinely taken one out to 10K+ miles on Castrol 5w40 Euro and the engine still runs very strong at 140K miles.

This is my first Mercedes and I’ve got to admit, it’s the finest vehicle I’ve ever owned. It makes my Navigator feel like a log truck, lol. The engine is strong and amazingly smooth. Its only quirk is a slight play in the driver’s side wastegate actuator. Once the engine is fully warmed, the sound is more or less non-existent, but when it’s cold under a specific load and RPM, it’s slightly noticeable.

This UOA included a trip from North Alabama to Philadelphia and back loaded with the whole family and pulling a trailer with my 1000lb motorcycle, my riding gear and all the luggage. It did another trip from North Alabama to Enterprise, AL but it also included my wife’s bike loaded in the trailer. All in all likely 3000lbs of trailer and cargo.

My wife now wants her next car (when our sons leave the house) to be a red MB convertible lol. She loves this vehicle.

 

[MontePrix28]

This is my first Mercedes and I’ve got to admit, it’s the finest vehicle I’ve ever owned. It makes my Navigator feel like a log truck, lol. The engine is strong and amazingly smooth. Its only quirk is a slight play in the driver’s side wastegate actuator. Once the engine is fully warmed, the sound is more or less non-existent, but when it’s cold under a specific load and RPM, it’s slightly noticeable.

This UOA included a trip from North Alabama to Philadelphia and back loaded with the whole family and pulling a trailer with my 1000lb motorcycle, my riding gear and all the luggage. It did another trip from North Alabama to Enterprise, AL but it also included my wife’s bike loaded in the trailer. All in all likely 3000lbs of trailer and cargo.

My wife now wants her next car (when our sons leave the house) to be a red MB convertible lol. She loves this vehicle.

The rattle that you're referencing is actually normal for the M276 turbo engines, Mercedes has an LI on it.

Besides front covers leaking, the only other common issues we see with the engine is the plasitc line under the intake cracking (you'll get an intake air leak code and hissing from under the intake), sometimes turbos (but can be replaced without removing the engine unlike the M278), and we've been seeing the oil pump control valve wiring inside of the oil pan going bad, but it's only certain years that it's required to throw the check engine light for (17+ I think?), but otherwise will be a stored code. It fails open, so if you get the stored code w/o a CEL, it's ok to not repair.

 

[Panda87]

The rattle that you're referencing is actually normal for the M276 turbo engines, Mercedes has an LI on it.

Besides front covers leaking, the only other common issues we see with the engine is the plasitc line under the intake cracking (you'll get an intake air leak code and hissing from under the intake), sometimes turbos (but can be replaced without removing the engine unlike the M278), and we've been seeing the oil pump control valve wiring inside of the oil pan going bad, but it's only certain years that it's required to throw the check engine light for (17+ I think?), but otherwise will be a stored code. It fails open, so if you get the stored code w/o a CEL, it's ok to not repair.

Dude, you have no idea how much I appreciate this info! I’m not sure what an LI is, but if it’s something I could look up, I’d be glad to take a look at it. I was already looking up how much a new turbo would cost me lol, but I’m glad to know it’s something MB is aware of at least.

 

[thetricky]

The first sample I sent on the 6th just got to Polaris yesterday. . I sent that one a few days prior to the one for the GL. They both took over 2 weeks to arrive from my place in North Alabama. It takes two days to get to Indy and then spends the next two weeks dorked up at the Indy distro. It’s been this way for every single sample I’ve sent in 2025.

Not sure if this will help you or not, however, I have had these issues too sending samples to OAI up that way. I started buying the no postage paid kits through Amsoil, buy my own postage for $4 less than the pre-paid kits, and they go to the salt lake Utah lab. Still sent usps, faster to get there, no losses yet, and quicker to get results.

 

[Panda87]

Not sure if this will help you or not, however, I have had these issues too sending samples to OAI up that way. I started buying the no postage paid kits through Amsoil, buy my own postage for $4 less than the pre-paid kits, and they go to the salt lake Utah lab. Still sent usps, faster to get there, no losses yet, and quicker to get results.

Oh dang, I didn’t know they could be sent to the other labs. That’s great info to know! I’ll give that way a try once I run out of my kits.

 

[thetricky]

Oh dang, I didn’t know they could be sent to the other labs. That’s great info to know! I’ll give that way a try once I run out of my kits.

Yeah, the non-prepaid you can pick. Even though you are on the east coast I bet it would be quicker.

 

[53' Stude]

Great report. When I got HPL 5w-30 HDEO CK-4 oil I jumped right in. Going to shoot for 13k, sample then probably go 25k and sample then decide. Great oil psi in the 02’ Dakota with old school pushrod “MAGNUM” 3.9 v-6

 

[Panda87]

Great report. When I got HPL 5w-30 HDEO CK-4 oil I jumped right in. Going to shoot for 13k, sample then probably go 25k and sample then decide. Great oil psi in the 02’ Dakota with old school pushrod “MAGNUM” 3.9 v-6

I look forward to the UOA on that run!

 

[53' Stude]

I look forward to the UOA on that run!

You can see my 3k and 6k run. Some “members” here may think I’m crazy going 5w-30 in a vehicle spec’d for 10w-30 but I have the stones to be different and fully utilize an oil. As does member Carbon Steel and Stumpy.

 

[TwoC400s]

You can see my 3k and 6k run. Some “members” here may think I’m crazy going 5w-30 in a vehicle spec’d for 10w-30 but I have the stones to be different and fully utilize an oil. As does member Carbon Steel and Stumpy.

the fact that people on an oil forum go crazy over changing the cold weather rating is funny to me. Unless we're talking about -0 F cold start temps and lower, why would anyone get wrapped around the axle about going from a 10w and a 5w oil? (or vice versa)

 

[53' Stude]

the fact that people on an oil forum go crazy over changing the cold weather rating is funny to me. Unless we're talking about -0 F cold start temps and lower, why would anyone get wrapped around the axle about going from a 10w and a 5w oil? (or vice versa)

Good question

 

[4WD]

the fact that people on an oil forum go crazy over changing the cold weather rating is funny to me. Unless we're talking about -0 F cold start temps and lower, why would anyone get wrapped around the axle about going from a 10w and a 5w oil? (or vice versa)

Some here associate 10W with lower quality base stocks and/or on the positive side - less VM etc … Seems an EP or boutique gets around that …
Have seen some really low Noack numbers on good 10W-30 …

 

[TwoC400s]

Some here associate 10W with lower quality base stocks and/or on the positive side - less VM etc … Seems an EP or boutique gets around that …
Have seen some really low Noack numbers on good 10W-30 …

but we're talking about boutique oils here. If your older spec says 10w and you choose an over the top, overkill, boutique 5w, why in the world would anyone "think you're crazy." ???

 

[4WD]

but we're talking about boutique oils here. If your older spec says 10w and you choose an over the top, overkill, boutique 5w, why in the world would anyone "think you're crazy." ???

I’m not saying people go crazy over it … that’s like my engineers saying “I heard you hate this equipment” - in reality I asked if it was fit for purpose …