UnLeaded fuel for 230.4

1968 - 1976: 220, 220D, 230, 230.4, 230.6, 240D, 250, 250C, 250CE, 280, 280E, 280CE, 300D
Post Reply
A Class
Posts: 10
Joined: Wed 15 Mar, 2017 11:07 am
Model you own: I own multiple different models

UnLeaded fuel for 230.4

Post by Driver » Thu 15 Jun, 2017 8:41 am

Is it necessary to use an additive in unleaded in a W115 230.4 or will they happily run on unleaded?

User avatar
300 SLR
Posts: 2008
Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: UnLeaded fuel for 230.4

Post by Bartman4800 » Thu 15 Jun, 2017 9:48 am

Every mercedes after 1950 has hardened valve seats in the cylinder head.
No need to add an additive.

Consensus here is though, to at least use RON 95 fuel.

1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

User avatar
Posts: 5846
Joined: Thu 01 Jan, 1970 10:00 am
Model you own: I own multiple different models
Region: New South Wales
Location: Dark side of the Moon

Re: UnLeaded fuel for 230.4

Post by AMG » Thu 15 Jun, 2017 11:58 am

Bartman4800 wrote:Every mercedes after 1950 has hardened valve seats in the cylinder head.
No need to add an additive.
Consensus here is though, to at least use RON 95 fuel.

Yep, covered a bazillion times. Use NO ETHANOL. so in most cases that is 98RON, because most 95 is now also being blended with ethanol. Always check at the bowser before you fill it.

Car will run much better on 98 if you tweak it as well. Less critical on carbs, but my own opinion is that any D-jet or K-jet car should only ever run 98RON and regular fuel filter changes to ensure contaminant free fuel systems. Prevention is far better than the cure.
1987 560SL 4sp. auto Signalrot "Stella"
1987 190E 2.3-16 5sp. man. Blauschwarz "Hermann"
1992 300CE-24 6sp. man. Perlblau / Iceblau "Gretel"
1992 Range Rover Classic 4sp auto Ardennes Green "Oswald"
2012 E63 AMG Speedshift MCT Diamantweiß "Klaus"
1986 560SEL Anthracitgrau "Schultz" - In Mercedes Heaven
1987 190E 2.6 4sp. auto Signalrot "Sabine" - which now resides/owns Andrew M's Garage
1972 350SLC Astralsilber "Lurch" - now in the loving care of Craig B
1989 2.5-16 Blauschwarz 4sp. auto (parted) formerly owned by Derek/Hasan.
2012 Renault Sport Megane RS265 Trophy 8:08 6 sp. man. Liquid Yellow "Jean Rédélé"

User avatar
C Class
Posts: 29
Joined: Fri 18 Mar, 2016 2:48 pm
Model you own: w108
Region: Victoria
Location: Watsonia Vic

Re: UnLeaded fuel for 230.4

Post by VFRBoy » Mon 20 Nov, 2017 10:04 am

Can I ask why no ethanol? I like the 95 e10 in my other (modern) cars, same price as normal 91 but the tech picks up the 95 and gets better performance.

What does the ethanol do to a 51 year old Benz?
1966 W108 250S
4-speed floorshift

Carn the Dees...

User avatar
Mercedes Demigod
Posts: 5884
Joined: Sat 12 May, 2007 2:21 pm
Model you own: w204
Location: Melbourne

Re: UnLeaded fuel for 230.4

Post by Ivanerrol » Mon 20 Nov, 2017 7:12 pm

Your car was originally tuned for Super leaded fuel. This was leaded 98.
Modern unleaded 98 is an equivalent , the octane rating is just enough to be considered the equivalent to leaded 98. The real octane equivalent is unleaded 100. It's the chemistry.

Ethanol contains a little moisture content which is handled better by modern engines because they run much "hotter" than historic designs.
The chemical properties of ethanol attack the rubber compounds and other seals of older design engines.

The government of the day attacked Mercedes and other Euro manufacturers when ethanol was introduced and forced them into issuing certificates of compliance. A very political subject.

And F.W.I.W. Australia has crap fuel. Produced by refineries which should have been retired or upgraded decades ago. 98 is imported from Swingapura.
W211 - E240
W204 - C280
W202 - C200, C180, C180
W126 - 380SE , 380SE (Ex SA Import), 560SEL
W124 - 300e, 260e (ex Japan)
W111 220s (Indonesia) 4 speed manual column shift
W123 230
W116 450SEL
W140 420SEL
W210 E240, E240
W209 CLK 240
W201 190e 2.6 (ex U.K.)

Post Reply

Return to “W114 and W115”