[Theo]

I'm taking it in for the 3rd official annual service in May, and I'm saying official because I do an oil change every 6 months so in between two official there's an unofficial, and I got an email saying what's included, and spark plugs are on the list. I'm at 42.5k km, when are they supposed to be replaced? I drive the car like it was meant to be driven, a lot more often than not. Oh and oddly the email doesn't say anything about the rear diff. Thought rear diff oil was changed after 3 years.

 

[Theo]

Spark Plug - NGK SILZMFR-87H 1391591400 - GENUINE MERCEDES

Spoke with dealer and they confirmed that the MB part number is A1391591400 which is the same for all models with the M139 engine. Just placed an order today, hope they make it in time, or the 3rd service will be done without it and will have the plugs done at a later date. Btw thanks for the heads up, you've saved me 2 months of waiting. Dealer also said they're replaced after 3 years or 60k km so I still have time, good thing the car is still stock so the change isn't urgent. At currently 42.5k there's no way I'm getting anywhere near that, and worst case they'll be few months overdue, not the end of the world.

Someone please sticky this. Actually let's put all consumables with their MB part numbers together. Everything we find as our cars get older. Easier to read.

 

[Theo]

On the service thread I have posted that I have taken out a new 48 months service plan. For me staying with MB for a high performance car like ours is a price hopefully worth paying. But it also validates the 30 years roadside assistance and rust cover.

The biggest dilemma I now have is which, if any app updates to buy before mid April 🤔

I bought them all a month ago, for another 3 years (each containing several individual services):

1. Vehicle Setup (QEV111AG2UM6)
2. Vehicle Monitoring (QEV111AG2UNB)
3. Live Traffic Information (QEV111AG4IST)
4. Online Map Updates (QEV111AH1XA2)
5. Navigation Services (QEV111AH5955)

Total cost €635.

Couldn't do without the 2nd update for security reasons, same for 3rd as live traffic has saved me so much driving time, 4th well obviously can't do without map updates, and as for the 1st and 5th well I wish I could only pick a few individual services within these packages, for example for 5th I only wanted the weather forecasts, not parking spaces near me or POI, and for 1st I only wanted the save profiles service (lumbar, mirror settings, radio stations etc) and smartphone notifications in case of damage etc, didn't care about remotely opening the sunroof or whatever. And then I was like, 1st is like €99 and 5th €139, so I've already spent 635 - 139 - 99 = €397 on the other 3 updates which I definitely want, €238 to have the remaining two for 3 years is no big deal. And I got them all. That's how marketing works right? You buy this, you buy that, and since you got that, you need the other one too? Such an old trick. And I fell right in.

 

[Theo]

Ok so we've established that A1391591400 which crosses over to NGK SILZMFR8B7H is the only way to go.

However, if you go to NGK.com you'll see that SILZKFR8D7S is listed as the correct fitment for the 2020 CLA45, in other words for the M139. I get that we should be careful of resellers trying to send us the wrong plugs (knowingly or not) but this is NGK themselves saying they will fit. Could our plug maker be wrong?

And a word about plug longevity. Again on NGK.com if you scroll to the bottom of SILZKFR8D7S specs, it says 100k miles. I don't see the SILZMFR8B7H on there (search shows no results) but I don't suppose they have different longevity. Now for them to last 100k miles, I don't know if it requires granny driving, but in any case, 40k miles is less than half that, so we should be safe up to 60k km which is what dealer said, whether it's you or your wife behind the wheel.

 

[Theo]

Can I ask something? It's quite common for tuned turbocharged vehicles, mostly full bolt-on setups and beyond, to upgrade the plugs to colder ones and/or with smaller gap or gap them to your specific requirements. I had grade 8 iridium NGK plugs on my fully bolted stock turbo ED30 GTI that made 390hp, which came from the factory with some 6 grade platinum plugs, from Bosch iirc. Before completing the stock turbo setup, somewhere halfway, I went to 7 grade iridium NGK and as I said ultimately wrapped it up with the 8's paired with R8 coils. Pretty common for these cars, including Golf 6R, Leon 2 Cupra and 8P S3 which all shared the same engine.

So how does that work with our A45s's? Suppose we start tuning our vehicles, aren't we supposed to eventually upgrade the plugs? Or doesn't work that way here? Cause I was thinking, if we were to upgrade to say 9's, there should be an aftermarket plug that can fit. Unless our OEM plugs are good for all setups, including the G30-770 that you're building @Turbo Ed. Frankly, keeping the OEM plugs for any setup beyond stock turbo, is unheard of.

 

[Theo]

@Theo,
Always!!

Of course, your general outline is correct.
Higher Brake Specific, colder plug, as a rule.

However, in NGK's heat range system, an 8 is pretty cold plug.
Most production engines use a 4, 5 or 6.
The Golf R uses a 7.
The 8 used in our cars would be the coldest plug, using NGK's system, that I have ever heard of in a production engine.

That said, I think you are rather missing the point.
Currently, there is no other plug, of any heat range or design style, from NGK, Bosch or Denso, which physically suits our engine.

So, currently, literally no choice, whatever you might like to try.

No I got that it's about physically fitting our engines, I just didn't expect that there isn't an aftermarket option that can physically fit, even if it was a 9, which I would give a try. I expected there was at least one plug maker that made a more suitable plug for a tuned M139, in which case, I think we would all try, given that our OEM plugs currently require an intelligence agency to track down.

So what are you gonna do? You have already placed an order obviously. What's your mileage? Are you gonna stop dailying your A45s until your plugs arrive? I'm gonna try and go from 400km/week down to 130, so that's 1/3 of where I was, just in case.

 

[Theo]

Quite frankly, had I known all this, the difficulty in tuning our engine, the difficulty in sourcing what should rather be taken for granted, the temp issues, I might have waited two extra years and gotten the RS3 instead, even if aesthetically the A45s wins hands down. But was it worth all this? And the plugs thing just topped it off, I mean seriously that's unacceptable. And the irony is that MB sent me this email saying there is a service coming up which will include the plugs, but when I get there in a couple of months, there will be no plugs to install. And if I hadn't made the smartest move to join this forum, and if it weren't for everyone helping each other out, I wouldn't have known this to at least place an order in advance. Fck this!

 

[Theo]

I feel for you too.

If they're now saying there is a 2 week ETA, they have likely found a set of plugs for you, likely reserved for emergencies as @Turbo Ed said. I would wait it out for now.

What happens if the plugs haven't arrived after 2 weeks and they say you're gonna have to wait longer.

I would contact MB UK directly, explain the situation and if they appear to be in line with the dealer, I would threaten with a lawsuit, based on the fact that they have advised that the car shouldn't be driven with current plugs, which means they acknowledge that the probability of engine damage because of failing plugs is significant, given the extended, and ultimately "undefined" length of time until the plugs are replaced.

If the car now suddenly became "driveable" I would ask that they take full responsibility in case of engine damage and make them sign it, otherwise we're back to the lawsuit.

I don't know what else to advise you, it's a tough situation. Just makes you wonder if you'll stick to MB for your next car, I certainly am having second thoughts. The tuning difficulties are nothing compared to not having a car because of one of the most common consumables in the industry missing. It's sad and hilarious at the same time. How did they fck this up?

 

[Theo]

Dealer called a little while ago, saying my plugs have arrived. Trying not to be excited until I pick them up later today. I'm debating whether I should purchase the most sophisticated, multi layer protection safe and put it in, or keep in a safe deposit box.

 

[Theo]

Which service are these plugs for. You already had some before which I am guessing you used for the current year service.

3rd year service in a couple of weeks, pushing the dates back a little in hope that either the gearbox gasket or the 235.64 oil arrives and include it in the service. These are the only parts still missing. I doubt they're both arriving in time though, so chances are I'll be going back a second time to complete the service.

Happy days though

A little under €100 btw, for the set. Sure wasn't expecting that!

 

[Theo]

Seems like I got them €17 cheaper. I was expecting something like €250 to be honest, only because AMG and NGK partnership is monopolizing the plugs. Who wouldn't pay for the only plug that can fit even if it cost three times as much, or four times, five times. Pleasantly surprised.

 

[Theo]

Btw they picked my plugs from a box that contained another two or three sets, which means the next couple of owners that take their A45s's in for their 3rd year service will never know anything about what we've been discussing here, be a normal spark plug replacement on a random Monday. Crazy, if you think I spent hours searching online. Timing is everything, isn't it?

 

[Theo]

No discount that I can see, four plugs €97.96 incl. 24% VAT. Before VAT it's €19.75 per unit.

It's not the same for all types of products and services. Everything about vehicles and computers is on 24%, 13% on most food products, hotels, restaurants and 6% on drugs, electricity, theaters and concerts, magazines, newspapers, books etc.

That 24% is among the highest in the EU, 4th highest I think.

 

[Theo]

I don't wanna talk politics but the Greek banking crisis got a big boost throughout the years 2015-2019 and mostly after what happened in the Summer of 2015. What followed next was the aftermath. "The government you elect is the government you deserve" - Thomas Jefferson.

 

[Theo]

Does make me me exceedingly grateful for "only" 10% !!!

We'll get there some day. You'll be on tax refund by then.

 

[Theo]

Now THAT was cruel!! (Even for you!! )

However, I suspect you are wrong, unless you can show me a country where a given tax was ever REDUCED!!

Trust me, you'll be buying wholesale by the time we get down to 10%.