PNBLWZD

I’m curious to know the group’s opinions of scheduled maintenance when the car’s mileage estimate of 10k/year has not kept up with the years. This does not include engine oil and filter, as that’s done annually regardless.

For example; last year my 2016 was due for the 5/50k service, which would have included spark plugs and engine air filters. But since my car only had 35k miles, my independent mechanic said spark plugs were not necessary and just inspected the filters which were fine.

This year it’s time for 6/60k service and the car was driven a little more in the last 12 months and has 44k miles now. So Im wondering is it time for last year’s spark plugs now since it’s closer to 50k miles? Also the 60k service calls for transmission service, but at only 44k miles is that needed yet?

Input is appreciated. I know the dealer service dept sticks to the calendar as it’s a money maker for them, but is it really necessary? Thanks.

chassis

Do all of it.

Plugs
Engine and cabin filters
transmission fluid replacement
brake fluid replacement

cfmistry

I stick to the mileage schedule over the calendar schedule. Of course using some common sense; I would not let 5k mile oil sit in the car for 5 years and I would not let a paper filter sit for 10 years. But within a couple years, I generally don't mind exceeding the calendar schedule.

I have used this logic for every car I've owned over the past 20+ years and it has never steered me wrong. Use is much more important than time; a car sitting idle not driven for weeks is where you get into trouble - regardless of the car.

2012 merc amg

Ya, the plugs in for too long a time might be more likely to corrode in the heads and be real hard to remove.

badq45t

I bought the pre-paid plan when I bought my car in 2019, it was a CPO 2016. They dealership did the plugs which surprised the hell out of me since my Nissan XTerra had 100k plugs and my other cars were typically 60k. But for sure fluids that sit are not better when not driven. I only have 39k now and I have one last pre-paid service and I plan to ask for all filters, tranny and rear end fluids whatever I can extrac out of them.

With full synth oil i am usually fine to run for 1 year but I check levels, i run Amsoil in my other cars not sure what I will switch to after my factory warranty is over I was never huge fan of Mobile One but seems like MB is pretty attached to that brand.

Tom in Austin

Opinions? I would say do all the fluids at the recommended intervals or miles. Oil gets contaminated with combustion byproducts and moisture. Brake fluid absorbs moisture over time. Transmission fluid accumulates gum, varnish, etc. These conditions cannot be readily observed or measured without sending out to a lab for analysis, so safest to just replace as recommended.

Filters and spark plugs can be inspected but again, I would just trust the mfg recommendation.

The rest of "servicing" consists of lubricating things like door hinges, sunroof tracks, etc. and inspecting for wear to undercar stuff like brakes, CV joints, exhaust, etc.

DaveW68

MB puts the Mobil 1 badge on cars in the US because M1 pays them a ton of money to do so. The oil in the car when it leaves the manufacturer is Fuchs Titan Supersyn Longlife 0W40, a German made oil also used in other German cars. My local mechanic uses this oil at oil changes.

DaveW68

Actually, the fluids can all be tested on the spot for moisture and contaminants with testing strips. No need to send samples to a lab. There's really no need to change the fluids at the intervals that MB "recommends" if the fluids are still in good shape. Unless of course you have deep pockets and just don't care.

Mitch Alsup

Just a note: After 5 years but only 32K miles, I allowed the dealer to replace the spark plugs (the expensive service) on my S-600, and it has not run as well since :: going from running perfectly to running with a very slight stutter.

But I have all my fluids changed at the std intervals.

DaveW68

My guess is that they didn't gap the plugs properly or a coil pack isn't seated properly on one or more plugs.

Highline-Autos.com

I would never hit the milage for service on my Mercedes, but would follow the time intervals. The approx. $800 a year in maintenance was all I had to due, bedsides my front air struts, but that is not related.

MBS63AMG

I use Motul oil in my car. 100% synthetic oil. It's $17 per quart but worth it.

PNBLWZD

Thanks everyone for the great input. I’ll go ahead and have the spark plugs replaced, making sure correct gaps are set, and have the transmission filter and fluid done despite low miles since it’s been in there 6 years. Happy thanksgiving!

badq45t

I can tell you 100% my car didn't run any different before and after the spark plug repairs. I am glad I did the pre-paid i think I made out on this as I bougt the CPO car from dealership that wouldn't negoitate much (got them to go frm 59k to 58k) but the extended warranty and service I got them to take nearly 60% off their first price. So far they are winning on the extended warranty, if I had know COVID was going to hit and I would have no place to commute to anymore I would have banked that money.

Next service I try to milk as much out of them as possible. Happy Thanksgiving ALL

PNBLWZD

I think the spark plugs are more of a preventative maintenance thing and won’t necessarily make a noticeable performance difference. Some mfg’s suggest plugs last 100k miles though, so Merc is likely being overly cautious with the forced induction engines.