Had my 2015 E400 coupe serviced yesterday (B service) and it cost a freckle under $1,300 which i thought was high although they did change the engine air filter. It was interesting as it only has 29,000 kms on it but the guy told me i should change the spark plugs @ $475 because they were 4 years old. I told that was rubbish and not to bother. He said he has seen these cars at this mileage suddenly start misfiring due to the breakdown of the plugs. Thoughts?

I did intend on trading it in on the new C43 but having found out it is now replaced with a C53 i need to research the new car's ride to see if it is suitable for an old guy like me.

Just trade it in. You are trying to justify something you want to do.

You know that service recommendation is absurd... Buy from another Benz dealer.

According to the U.S. 2016 Model 207 Maintenance Service Sheet (which I got from the dealer), spark plugs should be changed every five years or 50,000 miles. In the U.S., Service B costs about $500-$600.

When mfg changed to platinum plugs long time ago, the replacement for the plugs was 100K for a long, long time. I started using platinum plugs long before the mfg started using them. Recently Porsche, which I own one, wants me to change at 50K . Now Toad mentioned MB states to change at 50K.
I feel due to the lengthy 100K in the past, both mfg and dealers were making less profit. I think the 50K is a ploy to make money. Harold in Sydney stated that his dealer wants A$475 to change the plugs which is ridiculously high!

Engines were achieving 100k miles on platinum and irridium plugs when they were port injected and looser emissions standards. Direct injected cars, especially turbocharged ones are more abusive to spark plugs.

I don't believe plugs 'time out' like aircraft parts. But I have had the threaded barrel of the plug fuse to the head and snap the core of the plug right out. On different cars with long plug change intervals, that is... I think it's a galvanic corrosion issue of dissimilar metals of Steel plug on Aluminum heads.

My ‘11 E550 coupe has a tad under 32K miles on the original plugs so..... I’ve decided to replace them.

A quick youtube tube search shows that replacing the plugs, which are on top of the engine under the two plastic covers, to be about a one hour “novice” level job. Via Amazon, 8 spark plugs cost about $70 w/ free shipping.

The “B” service, in addition to checking fluids, brakes, tires involves the tech to sit in the drivers seat and check the operation of the controls and switches. Something we can also do ourselves.

I do do take the car to the dealer every two years for a service and brake fluid flush. Using a discount coupon.

It sounds like the B service is only a very short job. I won't take the car back to the dealer for the next one.

Actually, Service A is the smaller job; Service B includes a lot more tasks than Service A.

And A and B services are only the basic items that are covered every occurrence of them. There will then be a list of additional items based on age and mileage to add on top. So trying to compare one B service to another at different years is unlikely to give the same results.

You then have different service intervals for different components based on the engine and year manufactured. For example the year / mileage of the gearbox oil changed at the time of the facelift from 40K to 70k.

I have a 2014 E350 AMG Sport with 40k miles and the B service is due, main dealer is wanting £800 to do it. Apparently £500 of that cost is to change the gearbox oil and filter..

Try a local independent for the gearbox at least. If they have access to Star Online they can update the online service record as well. The gearbox service for mine with the 7G+ box was £169 with the indie, rest of the service was £120 (your may be more here being the larger engine).