Specail Truck-Stop Fuel? - PeachParts Mercedes-Benz Forum

#1 08-19-2002, 03:04 PM

My father was in Ohio with his 99 E300 and he filled up at a truck stop. Gingerly dripping the fuel from the large spout, he quickly noticed improved power, milage and response. He clocked 250 miles on a little more than a quarter tank. The guy at the station called it "grade A 45 diesel," I assume he was talking about 45 cetane. Any input about what was with this fuel? Was it perhaps fresher than if we filled at a local suburban station?

#2 08-19-2002, 03:15 PM

Hey Randall, is that source local?

#3 08-19-2002, 03:16 PM

Oops, just re-read "Ohio." I don't suppose that would be Ohio, NJ, would it?

#4 08-19-2002, 04:06 PM

Hey mccan, I'm affraid its the state... My mistake!

#5 08-19-2002, 04:41 PM

I don't actually know of a Ohio, NJ. Was just trying to sound less stupid. How'd I do?

#6 08-19-2002, 05:53 PM

Yep, that last sentence of yours is right. Truck-stop diesel IS fresher than regular service stations.

#7 08-19-2002, 06:54 PM

Truck stop fuel is fresh for sure, but I think it depends on the state and grade for MPG. I stop at Flying J's when on the road in Florida (always lowest cost) and the fuel is fine, but I don't get the MPG I get from the Mobil down the street.

slowmoe · #8 08-19-2002, 08:51 PM

So, was it the fresh-ness or the cetane that increased MPG? Both?

Wasuchi · #9 08-19-2002, 10:28 PM

Fuel really can vary from state to state or station to station. I filled up about three weeks ago in NM (not in my 300D, my F350 Crewcab pulling a heavy trailer) anyway my mileage on that tank was down to about 9mpg, I usually see at least 12. Got just south of Amarillo and filled up again, back to 12+mpg. Both fill ups were at busy truck stops.

190D22 · #10 08-19-2002, 11:41 PM

Aren't truck stop pumps a lot higher pressure than gas station diesel pumps? Since truck tanks are so big they can fill up a lot quicker. I know that diesel nozzles are bigger diameter so gassers don't fill up w/ it...

I wish I had a truck stop closer than 10 miles... Get me some nice diesel.

jobah · #11 08-20-2002, 10:15 AM

Pacific Pride stations in Western Michigan carry 50 cetane diesel (amoco brand). It is usually tested to be about 52-53 cetane. To use the stations, you have to provide a fein number (i.e., you need to run it through a corporation). But then you are able to use the stations. I usually get about 36-38 mpg with 40 cetane, I get about 40-42 with 45 cetane, I cannot imagine what it would be with 50 cetane on a regular basis.

stephenson · #12 08-20-2002, 02:03 PM

I wish I knew more about the topic or had ever seen metrics on this issue ... it seems reasonable there would be SOME difference based on CETANE and/or freshness, but I can't imagine there being 15% better fuel mileage based on CETANE ... is there a parallel with regular and premium gasoline?

Normally, gasoline is gasoline if it doesn't ping ... might get a bit better power and mileage if your engine can modify timing to take advantage of higher octanes with suitable compression ratios, etc ... but 15% seems high even in a case where electronics play a big role ... not the case with most diesels, right? (I know electronics are playing a bigger role, but 15%?)

jobah · #13 08-20-2002, 02:19 PM

it is my understanding that the engines were designed for 50 cetane diesel. They run remarkably better with better fuel. I have owned the car for so many miles and driven it through all types of conditions, I can immediately tell when I use better fuel, and it does generally provide me with better mileage. On one trip last year (over 300kmi on the engine), when I filled up with 50 cetane, I got better than 42.5 mpg whereas I normally get about 38 for the same trip, conditions, load etc.

The differences are REAL.