What gas to use?

[russelljones48]

I'm new to this forum, so please bear with me.  I purchased a 1967 230SL (yes, one of the few '67 230's) for my wife - her 60th birthday present.  I have other new and classic cars and have researched the in/outs of modern fuels.  My questions are these:

1.) what fuel is the "best" to use for this car - i.e. type and octane rating.  My car appears to be a 70,000 mile mostly original car with good maintenance having been performed over the years but it's still mostly original (I think).  I am using what's called "recreational gasoline" here locally (non-alcohol) that's approximately 85 octane.  Are there any combos with additives needed or changes to timing etc. required?

2.) Is there a way to determine the complete history of my car through MB archives or other means? 

Pointers to discussions on this site are welcome...  thanks in advance

Russell

[JamesL]

Welcome Russell - you do realise we need pictures (of the car...). And posting pictures is a bit of an initiation

On the gas, you might want to go a bit higher than that ie, the expensive stuff. The valves etc should be fine with unleaded without the need for additives but I think you'll find most of us run cars at 91 (RON)+. Yes, you'll soon learn that we have different terms and measures for pretty much everything...
So my 91/92RON is your 87/88

For a special treat I'll give mine (your) 92/3. But it's getting tough to find the stuff without alcohol/ethanol added


All MB will be able to give you is the data-card - ie the birth certificate of how it left the factory. The rest of it is detective work, I am afraid... Some folk have had great luck finding old owners etc but it's pot luck

[WRe]

Hi,
owners and workshop manual say that the optimal fuel has 96 ROZ (Researched Oktanzahl/Octane Number) but minimal 90 ROZ with adjusted timing.
But European and US octane rating is different. At European gas stations fuel is rated with ROZ/RON.
At US gas stations octane rating is a average value between ROZ and MOZ (Motor Octane Number) called AON (Average Octane Number) where MOZ is much lower than ROZ: AON = (ROZ + MOZ)/2).
Examples:
                                              ROZ              MOZ                AON
Normal                                     91                82.5               86.75
Super                                       95                85                  90
Super Plus                               98                88                  93
Ultimate                                 100                88                  94

...WRe

[Jordan]

Russell, yes pictures are a prerequisite for getting any info.

I fill up with 91 octane gas here (the highest rating at most pumps) and look for ethanol free gas. Some stations, like Shell here, have ethanol free gas for their highest octane rated fuel, which works out great for me.  There are also web sites set up to let you know which stations have ethanol free gas.  Most of the stations around here are not self serve (still old school) but I always pump my own gas.

I'm going to guess you are the same russelljones that purchased the 230SL on BaT in July?

[russelljones48]

thank you all for the prompt responses.  I'm in the Charlotte metro area in NC and we don't have access to 90+ octane non-ethanol only the ~85 octane I mentioned.  So, my corollary question is what are the downsides of using E10 or E15?  I run E10/E15 in my 1970 Camaro but the engine and fuel system are new and upgraded and the car gets driven year round as will the SL.

Yes, I am the new owner of the red SL from Benicia, CA.  It was as advertised and I'm very pleased with the car as delivered.

Since this forum is a bit different than others I belong to - where and how do I post pics?  I was also a bit puzzled on how to introduce myself... and the car.

[Baybear]

There are a few stations in Charlotte with 90 octane ethanol free gas. See below.
Will
https://www.pure-gas.org/index.jsp?stateprov=NC

[russelljones48]

Thank you.  I've used that list for the last couple of years but there are at least 2 things occurring: 1.) the list doesn't appear to be updated very often and 2.) the stations in my area North of Charlotte have all told me that their distributors are no longer selling/supplying 90+ octane non-ethanol fuel.  A sad problem but it looks like the market won't support it or the refiners are backing away from the product.  I do also want to be able to make longer than 1 tank round trips.  I live close to a small airport and have access to Av gas but that presents it's own challenges as well for a car that we want to drive around regularly.

[Bonnyboy]

Check the local marinas as they may still have the higher octane ethanol free gas. 

[mdsalemi]

Hi Russell,

I was just in Mooresville for the past week. I swear I saw a few stations that advertised "no ethanol gas" around, but I couldn't tell you where! Being the absolute race car capital of the world, I'm sure you can make a few calls or stop in a few of the race headquarters and simply ask a few questions.

That being said, I've been running E10 premium fuel in my 280SL since forever...which is since it was restored back in 2000 so that makes it quite a while. Aside from one leaky hose, the one connecting from the fuel feed pump at the rear of the car, that connects to the hard fuel line, I've had no issues whatsoever.

Yes, there are known issues with ethanol, nothing of which is new. Keep Stabil 360 in your tank if you use your car year round, and just be aware that you may spring a leak now and then...but one fuel hose in 18 years? I'm not complaining!

Oh, BTW--the following places near you (all marinas) sell ethanol-free fuel:

Holiday Marina, 20139 Henderson Road Cornelius, NC 28031 (704) 892-0561
King's Point Marina, Cornelius
Peninsula Yacht Club, Cornelius
Skipper's Landing, Troutman

[russelljones48]

Thanks, I do use the non-ethanol for all my yard equipment and the octane rating on my local source just went up to 90...    MOSTLY - though thanks for the verification of use on the E10.  I use it in my 1970 Camaro but it has a new fuel system.  Since my car appears to have mostly old hoses I will get them changed out and try E10... 

I have TONS of questions about this car but I can't seem to figure out where to post my questions??  Direction on that would be a great help...  for instance

Did the car come with hood insulation?  Mine has some kind of foam pad on the underside of the hood nut it's deteriorated and needs replacement (or elimination)

If you have time let me know the next time you're in Mooresville.

rj

[mdsalemi]

Hello Russell,

Good news for you is that we are contemplating a move to the area in the next 12-24 months. My car will come with me.

The car did NOT come with hood insulation. The hood, being aluminum, was part of the engine bay cooling system, absorbing and radiating heat from the engine bay to the outside. Many unknowing American Previous Owners, thinking it was missing or something, put some kind of insulation on the underside. Not only isn't this correct (and if you spend some time on the forums you'll see an overwhelming penchant towards "correctness" which is "as delivered") it interferes with the well thought out system.

The forums are divided into self-explanatory topics. Your initial question on Fuel, this thread, should technically have been posted in the form topic "Drive train, fuel, suspension, steering & brakes".  Questions on your external trim such as the chrome and aluminum bits, would go under "Body, interior, paint, chrome and cosmetic items".  Battery issues? Electrical.

Take some photos of your car, and post them under Photo Gallery.

[PSB]

Hi Wre,

Let me hijack your post....
Being in Portugal I have acess to the European versions as you describe, albeit most stations only have 95 or 98.
So what would be the recommended octane 95 or 98?
Thanks
Pedro

[114015]

Pedro...,

98 Octane (ROZ/RON) only,
otherwise you run the risk of pinging of your engine.


Achim

[PSB]

Thanks Achim.
I had started with 95 earlier this year , but as I wasn't happy with the performance I changed to 98. No idea if it does affect performance but the car is running better since then. Maybe the fact that it has now done 3000 miles since being "restarted" in a April after sitting for 8 years also helps.
Regards
Pedro