Jenncloud9

It was suggested that I use RXP. ​​​​I have never used a product like this. Only premium gas to help keep things clean. This wouldn't hurt... Would it?

C300CA

I know nothing about RXP and have only used Techron a few time in all my four cars, just because Costco often sells Techron at a reduced price. None of the cars shows any difference before and after the additive added in.
From my owner's manual, "... do not use fuel additives that are not tested and approved for Mercedes-Benz vehicles. Damage or malfunctions can result that are not covered by ... Warranty."

JohnnyC

I am not believer in adding fuel additives. Common petrol fuel already has additives in the US market, you might have heard of ethanol at a certain percentage.

And most of the fuel you fill up at common fuel stations have very very very very small contamination, but your car really won't notice it unless it is the wrong fuel or too much water.

Jenncloud9

Thanks for the replies. I am glad I checked. Seems best to not risk it.

C300CA

I fill in Costco gas 99% of the time. It's lower priced and it has more cleaning agent than some other brands, according to Costco statement.

dennish

IMO, It's not needed unless you use cheap gas. It doesn't hurt to use on occasion. Techron, Red line, or Liqui Moly are prefered brands. I use once every 6 months or so for added protection of possible injector problems.

tekfoc

dry gas is great, and BG44K is another great product.

Colin G

I use Chevron with Techron. I pour a bottle in the tank once every 2 months.

Cheap on Amazon.

If I lived in the USA I'd just use Chevron gas with Techron already added.

larrypmyers

If one is concerned about the quality of the gas your pumping into your car, switch to Top Tier gas.

Additionally, the Operator's Manual admonishes one not to introduce such additive into your fuel unless approved by M-B.

Bahnstormer

+1. This is good advice.

ezshift5

I'd be inclined to agree with the SK/FL input above....................

............ been using Chevron Supreme/Techron since this beautiful little coupe stole my heart..........................

......but not my wallet - - CPO/MBFS sealed the DEAL.....(two comp payments.+ two comp 10k services!)

all I worry about is that damn Takata recall (plus the battery is close to age 6.5)


ez

W204Motorsports

250k here and I use lucas fuel additive every few fill ups, when i first started using it at around 160k it was to fix an engine ping i was hearing from time to time and I have never heard it again after using Lucas. I also ran some seafoam threw the intake at 180k and again at 220k which seemed to help a lot. Also the PCV systems on these cars tend to get a lot of oil in the intake, specially from the passenger head. I put a catch can on that side and seafoamed it now my intake looks like new inside. After 50k there is no sign of oil in the intake and the catch can is doing a great job catching it, point is, without oil in the intake side of the engine, carbon wont be able to stick as well and you're engine will run better for longer, 250k and compression is still very strong and runs like new without burning or leaking a drop of oil.

C300CA

I heard from my colleague that lower Octane gas has more power? I don't bother going into that details. In the first 4-5 years I always used premium gas (91). Now I use regular (87) 90% times. No difference at all that I can tell.

W204Motorsports

Maybe you dont feel it but you're engine sure does, you're getting plenty of knock with 87 octane which is very bad for the long term life of you're engine, stick to 91 octane or greater, these engine ping and knock if you dont, maybe you dont realize it or hear it but I guaranty your engine pings and knocks.

C300CA

So nobody can hear engine pinging and knocking? What does knock sensor do? It adjusts the timing but goes out of its adjustable range?

W204Motorsports

Knock sensor does it's job but it can only pull a bit of timing out, you may not hear it but if you plug in a scanner and data log the knock sensors, I can guaranty there is a lot of it going on.

Here's a video, I tried that with my Icarsoft and got the same results when i tried 87 octane which I will never put in my tank again.

C300CA

Oh thank you for the video info. I don't have time to watch the entire video but you convinced me. I will probably buy that tool and start putting in 91 only. One time I saw an article saying for most cars (not truly sports cars), using premium is just a waste of money.

superangrypenguin

Urine works best.

bigrob126

I use Gumout "All in one". Your injectors WILL get a little dirty over time no matter what gas you use, and it's of good practice to use a cleaner/solvent every once in a while to help. This is why the dealerships offer injector cleaning service. The only cleaner I've used that has made a noticeable difference for me has been the Gumout. I've used Techron, Seafoam, & many others. Used Gumout in my '10 BMW 328i. I thought the car ran perfectly, No pinging and mileage was spot on, but out of habit I added the gumout, and it made a noticeable difference. Throttle response got better and the car got a little peppier. I have also seen tests by regular folks with gumout, with a camera in the combustion chamber, you could see the carbon on the top of the piston. It did clean up the carbon deposits on pistons, so it does work. And 91 octane is a must!

superangrypenguin

Gumout makes great products, BUT it is worth noting, that after a tank or two of gas after you've run something like gumout, change your oil. PEA is the main detergent in that, and even moreso in the Redline SI1 fuel system cleaner. Great at removing carbon, but because of its very low volatility and high effectiveness, it tends to end up contaminating oil and thus breaking down some of the oil's strength (flashpoint drops etc).

Anyways, it is minor, and IIRC on the instructions of those cleaners they do tell you to do an oil change afterwards, or shortly

bigrob126

n'Excellent point! It's bad enough that fuel gets by the rings and into the oil, it seems more so on turbo cars I've noticed, which can compromise the oil's integrity, but the solvent/cleaner added to a tank of fuel will undoubtedly get into your oil as well adding to the breakdown of the oil. It is most definitely a good idea to probably add your fuel additive at your last fill up right before an oil change. I try to do this, but must admit I haven't always been so on it!

benzw205

I agree, but wondering if it is what most people think ?
Is it possible to find a comparative video of cars having used additives for years and cars not using it ?
It seems like marketing BS to me, but I might be wrong ?

xsever

MB sells its own fuel additive. The part number is A000989254516. If they make it, I am sure it wouldn't hurt to use it once a year.

ezshift5

[QUOTE=Bahnstormer;7371782]+1. This is good advice.[/QUOTE

A Chevron Supreme (w/Techron) diet has been fed to our C250 coupe for 7 years. No issues there. (We did have an ESL issue at 39,000 miles - extended warranty helped with the one-grand tab).

ez