• The Forums are now open to new registrations, adverts are also being de-tuned.

Which spark plugs? 1988 300CE

Deadly Dave

Active Member
Joined
Oct 16, 2010
Messages
327
Location
Dublin, Ireland
Car
1988 300CE & 1965 230SL
I am going to do a full service on my 1988 300CE over Christmas. I got everything from MSL except for the spark plugs. They said they don't have them listed anymore.
Any recommendations please, does the new E10 fuel change anything?
Thank you.
 
6 x NGK Iridium IX Spark Plug TR5IX, according to:



Other NGK plugs are also available, but my understanding is that NGK's Iridium range is the best they make.
 
Hopefully you are not running a car that old on E10.....I wouldn't. Stick to the 97 to 99 octane stuff as that will be E5.... so 5% ethanol or less.
 
I would run it on 99 octane leaded if I could but in Ireland I'm stuck using E10 rubbish ☹️
Lol... even we can't buy leaded ... not since 1999!....but we can get fuel with a lower ethanol content, under 5 percent... for now at least. Just as well...because even some relatively recently Mercs can't use E10...like the 200 CGI for example.
 
Copper non resistor plugs. I think for NGK, it's BP6EFS. Non resistor is important
 
6 x NGK Iridium IX Spark Plug TR5IX, according to:



Other NGK plugs are also available, but my understanding is that NGK's Iridium range is the best they make.

Those are resistance plugs, not recommended for the m103. NGK BCP5ES are what I would go for.

Edit: Al beat me to it.
 
Those are resistance plugs, not recommended for the m103. NGK BCP5ES are what I would go for.

Edit: Al beat me to it.

No idea. I am just going by what NGK recommend:

Screenshot-20241223-163731-Samsung-Internet.jpg


Feel free to use whatever you think is best.
 
NGK BCP5ES or BP6EFS ?

Different heat range I suppose?

Hopefully they will take the TR5IX back.
 
Those are resistance plugs, not recommended for the m103. NGK BCP5ES are what I would go for.

This.

Non-resistor plugs only.

Don't be seduced by costly exotica when the real thing is cheap. Mine is the M104 engine and I got genuine MB ones a year ago.

Ideally, get the MB reference from an EPC or, as in my case, from a little label next to the radiator.

RayH
 
NGK BCP5ES or BP6EFS ?

Different heat range I suppose?

If you're engine is worn and you burn a little oil, hotter plugs will help burn the oil off. If plugs are too hot, they could cause detonation and damage the engine.
 
There's only 120k miles on her and I've replaced the valve stem seals before so she doesn't burn oil.
Mercedes have changed plug type over the years probably to allow for changes in fuel quality, so I was hoping they would recommend a plug for E10 but they don't .
 
Worth checking the main dealer for prices.

When I put new plugs in the SL500 the genuine parts were something like £2/3 a piece and you won’t be guessing on correct part numbers etc.
 
You plugs don't care what E rating your petrol is.....but you old rubber fuel lines and pump seals might.
The plug spec changed when we changed to unleaded petrol due to heat. I didn't know if the E10 would change things too.
I'm using an additive to stop the seals from dissolving and will replace the hoses soon.
 
Hopefully you are not running a car that old on E10.....I wouldn't. Stick to the 97 to 99 octane stuff as that will be E5.... so 5% ethanol or less.
I generally fill with E5 once a month , and the more readily available E10 the rest of the month , sometimes I only fill twice a month , sometimes more
 
I always buy from MSL - main dealer but they said they no longer supply or recommend a plug.
MSL have a good reputation but they’re not a MB main dealer - MB themselves will still supply these plugs I am sure :)
 

Users who are viewing this thread

Back
Top Bottom