gas additives

[n/a]

I just purchased a 1970 280 sl. I have used high test gasoline. Is this correct? Should I also use a lead additive. Appreciate advise from the veterans. thanks, Shelley

[Bob G ✝︎]

Shelly:
I would stick with a premium brand gasoline 90 octain for your car. I have not had to use a lead additive in my 1968 280SL. I would however recommend a fuel injection cleaner added to a tank of gas to help keep the valves and injection clean. Also these cars like to cruise at 4000 to 5500 on the freeway a good way to clean out carbon on the sparg plugs.
Bob Geco

[hauser]

I use a 93 octane from Chevron. I haven't had any problems so far. When I had my BMW I used an additive to keep carbon down to a minimum.

As far the engine oil goes I use Castrol GTX 20-50. I do not add any additives to the Pagoda but I did with the BMW.  I used liquid graphite.  Has any one ever tried this before?

1969 280sl 5 spd        1999 ML320          Gainesville,Fl.

[Shvegel]

I also have a 1970 SL. The valve seats in the aluminum head are already hardened steel and lead or lead subtitute is not needed. I always use the best fuel I can buy to avoid knocking(I keep my car tuned to a finer edge than the stock settings) I have also recently been adding NOx systems street formuls octane booster since the quality of fuel seems to have deminished this summer and I don't want to detune.

[mdsalemi]

Old British cars and some American cars relied on lead in the fuel for valve lubrication I believe, I don't think that it is necessary for the MB line of products.  Good old higher-octane 90+ will do you fine.

I've used Techron from time to time to "keep the fuel injection clean".  I don't know MB's policy on this but it is recommended by BMW.  Techron can be purchased at Costco if one is near you, or at Chevron stations on the left coast.

I got religion from Mobil on full-synthetic oils, and at Starfest they are pushing their 0W-40 for European cars.  They did not have nice things to say about Castrol, since it is manufactured in different plants under licence or contract with different base stocks thus the quality control is suspect.  They said that Pennzoil and Valvoline oils are made in ONE plant with ONE base stock with very stringent controls and these are preferred if you do not want to use their oils.

Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored

[George Davis]

Hauser,

I remember about 20 years ago that motor oil containing graphite came on the market for a few months.  What I heard is that the graphite actually was abrasive at high rpms.  I don't know if that's true, but the stuff didn't stay on the shelves very long.

George Davis
'69 280 SL Euro manual

[Cees Klumper]

I use Valvoline synthetic oil for my rebuilt engine.

When I lived in the US, driving my W 123 300 turbodiesel (one of the nicest cars I ever owned) around, my West Palm Beach, Florida MB dealership encouraged me to use Techron once in a while to clean the injectors out.

I have not seen Techron available in The Netherlands, but my car does not seem to be missing it. I always use the highest octane unleaded fuel (98, but this is according to a different standard than the US-count).

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[graphic66]

I add Marvel Mystery oil to my fuel at 4 ounces per 10 gallons to keep the injection pump lubed. I also use OMC Carbon Guard at the rate of 1 ounce per 16 gallons to help fight carbon buildup.

[rwmastel]

Graphic66,

I don't think that's necessary as MB never recommended (from what I hear) fuel additives of any type.  The 230SL uses it's own oil supply in the FI Pump and the later cars used motor oil thorugh a feed tube.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[Malc]

Others on this side of the pond include Redex and STP products....
We can get up to 97octane (RON) fuel but it's expensive, 95 octane unleaded is the norm....
My BMW20002tii seems to survuve on this, though I did have to knock the timing back a couple of degrees to stop it pinking (pinging). No problems re valve seats, but I did get bronze valve guides fitted when I re-conned the cylinder head.

FInally watch it when using a detergent/injector cleaner, some can be quite aggressive and will "lift" all the dirt and rubbish in the tank and then promptly bung up the fuel filter! Only use it to clean the first time when your getting ready to service your car.
Malc

[graphic66]

The reason for the carbon dispersing additive is that since about 1980 in the US the dispersants added to fuel have been eliminated. This was mostly evident in 2 stroke motors having a problem called ring jacking in the early 80's. This was a condition of carbon buildup on top of the rings causing them to slap the head and break. The industry responded with a repacement for tcw2 2 stroke oil called tcw3 with the dispersents added to the oil. The manufactures of engines also created product like OMC Carbon Guard to add to your fuel to further help with carbon buildup and aerosol cleaners such as OMC's engine tuner to be sprayed in your intake periodicaly to help remove carbon. This product is great for cleaning heads while rebuilding also, it just melts the carbon away. Newer car engines are designed to run hotter and cleaner and don't require the dispersants the older rich, cold running engines did. The 113 engine may or may not benifit from this. I have always run this additive in my older engines and think it may help with the preignition knock that can be caused by red hot carbon buildup causing the preignition in your cylinder by igniting the fuel before your spark plug fires. As to the Marvel Mystery oil. it has been recomended in these cars with mechanical injectors to periodicaly add 2 stroke oil to your fuel to keep the pump top end happy, so I think the Marvel Mystery oil may help do this. I have run both these additives in my fuel and my 230SL just keeps running better and better. Mostly because of the advice from this and the Pagoda113 sites from our very informative posters, Than You!

[rwmastel]

quote:Originally posted by graphic66

As to the Marvel Mystery oil, it has been recomended in these cars with mechanical injectors to periodicaly add 2 stroke oil to your fuel to keep the pump top end happy, so I think the Marvel Mystery oil may help do this.

Recommended by Mercedes-Benz?

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420