I've read posts on Bosch Platinum +4's and the opinions are mixed.

1. Is the engine in my 96 c280 considered an older engine that should avoid the Platinums? What is the differentiaition between the "older" engines and "newer" engines....engine management system, valves per cylinder, etc?

2. What are the original plugs on my car?

3. I'm interested in Plat +4 because I do a lot of city driving and would like to avoid carbon buildup as much as possible and would like improved throttle response in stop and go traffic.

4. Has anyone actually returned Plat +4 to Bosch because they were dissatisfied. Can you return it to the retailer for a refund?

the opinions/results for the copper core plugs are not mixed so why bother? only problem i had was finding them locally - finally had to get them at the dealership. my guess on your plugs are Bosch F8DC4.

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joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
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I have them on my 91 318is and they do a wonderful job. It certainly made a difference in the performance of the vehicle. Of course that is a high reving, high performance engine doc, dv's. I only run 91 or better.

If the engine came with copper core plugs, I usually stick with them. The reasons are many, but the main one is how small the center electrode is on the plats. I have seen a car foul one in 2k miles.

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Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

I use the +4 plugs in my '89 560SEC and also an E150 Ford 5.0 V8. I like them fine in both applications, although I can't say there is a dramatic difference between the +4 and anything else.

I tried Splitfires once in yet another (non-MB) car (guess I'm a sucker for gimmicks), they were advertised to improve fuel mileage or money back. I took the latter.

If the +4s perform okay as advertised for 100k miles, then it will be worth the expense for me, as well as avoiding the bother of setting the gap.

I have experienced no fouling of the +4s.

All that said, that is just the experience in my car, Benzmac has seen a lot more spark plugs than I will see in my entire life!

Tom

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CloudNine
'89 560SEC

I think that due to the very small surface area of a plat. tip, it wouldn't be too hard to foul one out. I think they would be best for a car that is in PERFECT running condition. One interesting note, I have read in several places that they are not recommended for turbo engines. Don't know why, but I thought it was odd that they weren't. I have gone to Fastlane to look up sparkplugs for my Passat (turbo), and Bosch plats are not availible. On the other hand, when I looked up a Beetle it list both regular Bosch and Bosch +4s with the footnote "exc. turbo engs."

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member

Here is my experience with +4's. I have a 91 Galant VR4, it has a 2 liter turbo engine and most of the people in my list suggests NGK's. I have been happy with the NGK's but wanted to try them.
No need to set the gap.
After I installed the +4's I noticed that low to mid was much smoother and what felt like the engine was much crisper. The problem I felt was that at higer rpm's, it felt like it was misfiring.
So if you guys do more low to mid rpm driving then I would suggest the +4's.

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96 Legacy LSi wagon
92 Mitsu Expo
95 525iT
1983 300TD clackclackclack sold
1972 Toyota Corolla wagon TE28 sold
1991 Galant VR4 pshhhhh non-op
1989 Montero RS pop's ride

Don't the new Mercedes' in which they advertise they have 100,000 spark plugs have the platinum plugs (+4's?) Why if they are so sensitive to fouling be used in such applications where change intervals are so long? Strictly different engine design? Are the new twin spark V-6's that efficient and clean?