Hi all,
I've been wondering these kind of things for a while now, it seems as if no fuel stations post their cetane level of the diesel fuel. Every station I've went to before and asked the attendant they looked at me all confused and reply that they don't know. So what did I do? I emailed the corporate websites of my two most common stations. I also read up on some older threads to find a few opinions that;
Sunoco doesn't yield as good as fuel mileage, not very good fuel.
Cenex is yields better than average fuel mileage.
Amoco makes a premium diesel with much higher than normal cetane levels, however it comes at a cost and is sort of hard to find.

After emailing Marathon Ashland Petroleum (CMS, Marathon, Speedway) they replied that:

After researching further at that site I found that in order to be claimed diesel it must meet two of those criteria. BP/Amoco hasn't yet replied, maybe I'll give them a call if they don't soon or I don't gain enough info here. Do you notice better mileage with any certain stations? Do you notice worse with some?

My own observations:
Sunoco is decent fuel, yields decent mileage
CMS is good fuel, yields decent mileage
SpeedyQ is poor fuel, yields OK mileage
BP is good fuel, yielded me my record mileage of low 30s on winter blend.

My biased opinion, I like BP because they have pay at the pump in my area and they pumps pump very very quick. Neither CMS or Sunoco use pay at the pump and both pump mediocre. SpeedyQ pumps the slowest, but uses pay at the pump. While biased opinions are fine, I wouldn't mind seeing some stats or facts, especially if you get better fuel mileage on one brand vs another.

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

Something you may want to consider when shopping for fuels is high volume turnover. You don't want to buy stale fuel, or dirty fuel for that matter. I too kind BP/Amoco the best, along with Texaco. Mobile cetanes (I've seen) are at 40, while a Gulf station near me sells 45! I like the Gulf too. If your are really concerned about the cetane, buy a cetane booster to get it high enough.

This is the operative part of your post: "Sometimes the supplying jobber will do their own thing..."

So you never really know what you're going to get. On the other hand all Hess stations are required to get their supply directly from Hess. The quality is consistent and one of our members in Sarasota had a fuel sample tested that came out at 47 cetane.

My seat of the pants evaluation is that all three of my Diesels love Hess fuel. They run far better on it than any other petroleum based fuel.

Biodiesel, however, is even better. Just this week I started experimenting with Biodiesel from Ward Oil Company in Tampa. The 240D is running 100% bio and seems to be much quieter and smoother. The Jetta is on a 20% bio mix, again with a noticable reduction in noise. I drove it yesterday and would have mistaken it for a gasser if I didn't know better. The E300 hasn't had a dose yet.

So if you can get the Hess, definitely try that. And if you can get biodiesel, try a 10% to 20% mix for even more improvement.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

I've never heard of Hess before, we don't have any here. I thought about making biodiesel but became lazy. I suppose the whole reason for this thread is I'm trying to find which station sells diesel with the most energy per gallon and best cetane level for the normal prices. I use redline DFC which will boost the cetane a few points, but still I'd like to know what I'm buying. I was hoping that there would be a concrete answer, but I suppose most stations get their own fuel from their own distrubutor.

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

I too have the same frustration with cetane and wish every fuel station posted it. A couple local Texaco stations advertise "premium diesel fuel" but the price is no different from any other fuel station so I doubt it's really premium, although my car ran a little better on it. By the way, the Chevron website has an excellent write-up on diesel fuel. I also try fuels from different stations and recently my car has been running a lot smoother at cold idle with diesel fuel from a local Shell station, though on the pump it says it's a local brand, not Shell fuel. I do add a bottle of fuel additive at every fill-up to raise the cetane even more.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

Mobil replied with some information that they require a min of 40 cetane, I get the feeling that is what Mobil brand diesel is and the fuel station has to use additives if they want to boost it any higher than that.

CMS call their diesel premium diesel, in order for it to be preimium though it must meet at least two of the previously stated requirements. Sure it is premium, but I think high cetane diesel (like amoco sells) seems to cost more. I rarely ever see CMS pricing any different than the other big stations. I only know of one shell station that sells diesel and their prices are insane, then again so is that whole area. It sure would be nice they posted the cetane on the pump just like the law requires the octane and the method used to derive that number.

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

BoostnBenz, your location isn't listed, where did you say you were, Michigan? You are in one of the few states that is able to get 50 cetane minimum Amoco Premier. Seek it out, and use it exclusively, it's by far one of if not the best fuel in the country. Minimum 50 cetane, low aromatics, low sulfur, better basestocks, great additive package, etc. You will have quicker starts, better mpgs, and more power. It's worth a bit of a drive to use.

Where in Michigan are you? There are a few places that sell Amoco Premier and Biodiesel. One place called Wacker Oil, sells a B20 (20% biodiesel) mix of Premier and Bio, talk about a sweet sweet mix!!!!

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2004 Ram 2500 Cummins HO
2000 Jetta TDI
1999 E300 (sold)

I've heard the Calif. and Texas require minimum 48 cetane levels. Some, however, say that fuel mpgs under Calif. fuel is less -- and my experience seems to bear that out. Anyone know why?

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'91 300D 2.5 Turbo 330K
'00 VW TDI Golf, 190K
'67 BMW R50/2
'73 Norton Commando Interstate

Indeed, there is a Amoco in Rochester. I searched their network for a place that carried it and I found the station before but never stopped in. Almost seemed like it was $.25-.30/gal extra there but I'm not sure.

I should find a restaurant around here and do that. WVO sounds pretty nice, especially the price of it.

California requires more oxygen in their fuel, so in a gallon of diesel you are also buying air for the price of the diesel. Isn't that great?!

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

More air, great...just like cheap ice cream. Thanks.

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'91 300D 2.5 Turbo 330K
'00 VW TDI Golf, 190K
'67 BMW R50/2
'73 Norton Commando Interstate

As an update, after contacting quite a few companies BP and Sunoco never returned the email so next time I go there I'll get the managers info then contact him and make him find this out for me. Being this actually varies per region it may not be worth posting the results here.

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

BoostnBenz, premier is worth whatever extra it costs. Hopefully it is in fact premier. When you fill , look, its usually clear with a slight green tinge..

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2004 Ram 2500 Cummins HO
2000 Jetta TDI
1999 E300 (sold)

#2 diesel isn't the most highly characterized fuel on the face of the earth. I happened to run into the cheif chemist at the Marathon refinery last week at European Connection, my local Benz indy's shop, and he admitted that diesel fuel production is basically distilling the proper "cut" out of the crude and adding the additive package and shipping it. Very little more.

Now, if you are in the market for molten sulfur, he's going to have trainloads of it in the near future......

He also said that with the current distrubution system, you are likely to end up with just about anything in anyones diesel fuel station, just what depends on where you are.

You will still have to shop around and see. My two local faves are Phillips 66 (known here are Circle S) and Shell. The Phillips smokes more in the winter, but starts easier, and the Shell smokes less most of the time (hard to tell on the 300D, it never smokes at all except on an occasional heavy throttle start), and give better milage on the average.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

psfred is right, most standard #2 diesel travels along the same shared pipeline, and is separated and branded/additized at the terminals. Amoco Premier and Bp Diesel Supreme are kept separate from the refinery to the station, the whole way, so they are not polluted with nasty regular #2. Those who have access to this TRUE premium fuel are very lucky.

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2004 Ram 2500 Cummins HO
2000 Jetta TDI
1999 E300 (sold)

I agree with Rick on Hess for what is't worth. Best bang for your buck so to speak. I commmute three counties for work every day, and find that they have the best consistancy from station to station. Texaco "premium" diesel seems to give a LITTLE better kick in the pants, but the $.30 a gallon differance doesn't justify the addition cost per tank. Only one Hess (in Brooksville) publishes the cetane rating on the pump that I frequent.