MPG discussion, this time around Cetane, total BTU content compared to price

[neoneddy]

I've been diving into fuel quality and which stations offer the best, or best that I can find.   It might all just be luck of the draw.  Here in MN we're mandated B10 I believe, I did find some #1 Diesel at a station, but it was $3.87 /gal, however that could still prove a good deal if the math works out.

Ok, so on a recent trip to SD, we got as good as 6.3 mpg and as bad as 5.5 mpg per tank (over similar stretches of road to and from).  Over 500 miles thats a difference of 10 gallons, more than just the angle of the bus when refueling or something.

Up until now I've largely bought on price, always looking for the lowest I could find, using gasbuddy, etc.   But what if finding the best quality for the price can more than pay for the difference.

Here is a chart I've seen around.  Ideally higher numbers are better I'm told.  I do know cetane has mostly to do with cold starting, but in any case I'm not sure all diesel fuel is created equal.

BP (Amoco branded), 51
Chevron, 49 (51 with Techron D)
ConocoPhillips, 48 (California 48-53)
PetroCanada, 47-51
Shell, 46;
Sinclair, 46
Marathon 45
Exxon/Mobile, 43-46
BP, 40-42 (Powerblend 47)
HESS, 40-45
Husky, 40 (Max 41-45)
Sunoco, 40 (Sunoco Gold 45)
Holiday Stations, 40-43
Love's: 40
Pilot: 40
Valero: 40
Sheetz: 40
Flying J, 40

So back to my example, let's say I filled up at 3.05 and it's lower grade fuel so  I got 5.5 mpg, over 500 miles that's 90 gallons for $274   But maybe you could find someone not selling the cheapest fuel but was better quality and got you 6.3 mpg over 500 miles that's 79 gallons for $248 total.   In this hypothetical scenario,  that's a little over $25 difference.

Now, how do any of us know exactly the cetane or BTU content of any brand's fuel?  Usually the pumps will tell you the minimum at best.   

I use a spreadsheet on my phone to track every fuel up , milage, price, notes, etc.  I added a column for Brand and stated Cetane if present, this way hopefully I can find a trend as I explore brands and not be so afraid of spending $.05 or $.10 more a gallon.  It's worth it to me anyway.

Curious if you guys have found any connection with fuel stations and MPG?

Edit: While not a 2 stroke test, there was an un official study done on cetane and milage. http://www.trucktrend.com/features/0911dp-fuel-additive-test/

[Iceni John]

What got my attention is the mention that adding 2-stroke oil can gain one MPG by increasing lubricity.   It sounds too good to be true.   I find it hard to believe that adding half a gallon of it to a 100-gallon tank of ULSD will gain one MPG.   More to the point, what Bad Things could it potentially do to a 2-stroke Detroit?   OK, I know the author is talking about a pickup truck getting twice or more our buses' fuel mileage, but still?

I've heard of folk adding Dexron ATF for the same reason, but that could be a problem if the DOT dips your tank when checking for red-dye diesel.

John 

[neoneddy]

Actually I tried putting ATF in the tank this spring, good chance plenty of it was in my tank on my first leg out to SD (when I got better MPG).

From what I gather, so long as there is no particulate in the fuel (like untreated / unfiltered used oil) the 2 stroke diesel will burn just about anything that is oil based.   I don't see how something more slippery can cause wear damage.

This adds another variable to my spreadsheet now.

Would be interesting if you could add something like a garden hose sprayer mixer to the fuel line, not that exactly of course, but the idea. https://www.amazon.com/Aqua-Plumb-Sprayer-Mixer-Bottle/dp/B0058I118E   

Add raw additive so you could turn it on or off and adjust mixture rates.

[lostagain]

Well...

This subject is going to elicit a lot of comments from key board petroleum experts.

Here is my opinion, based on retailing gasoline and diesel fuel for the last 26 years in South East BC. Our fuel is refined in Edmonton, then piped to "the rack" in Calgary, where it is loaded onto a B train semi when we order it. When one refinery is short of a particular kind of fuel, it gets it from a different refinery. So if you go to a station, you may not be getting what the brand says it is. So at least up here, fuel is fuel.

So when I need fuel, I just fill up. Yes it is expensive. But that's all you can do. Unless you go camping with a bicycle and a tent.

JC

[RJ]

Eddy -

Over the 45,000 miles we've put on our coach in the four years we've owned it, our overall fuel mileage has been 6.756 mpg.

Uphill, downhill, towing, not towing, flat land, mountains out west (not the east coast speed bumps!), genset running full-time, etc.

Best has been 9.42, downhill with a tailwind from Colorado Springs, CO, to Amarillo, TX via Lamar, CO (stopped to see the old Neoplan plant.)  Worst was 4.81, uphill from Taos, NM to Walsenberg, CO, starting at the 8,000 ft level with a whole bunch of 6% and 7% grades, which translates to 11-25 mph in 1st & 2nd gear in our rig.

Our MC-5C is geared to run 2100 rpm at 60 mph, thus sucks fuel at freeway speeds, and, with the anemic 6V71, can barely crawl over a parking lot speed bump. (This is my only real complaint about our rig - it's severely underpowered, otherwise it's a GREAT coach.)

I use GasBuddy all the time, always shopping for the least expensive when it's time for fuel stops.  I generally will not travel more than a mile or two off my planned route to save 2? - 3?, but if it's 10?/g, I might, especially if I know I need 80 or more gallons.

I guess what I'm trying to say is that in the overall big picture, when operating a bus that gets roughly 6.5 mpg over a 45,000 mile period of time, there hasn't been a whole lot of difference between price/gallon and/or cetane/gallon in my experience.

I'm also not a fan of additives you find on the shelf at WalMart or O'Reiley's, so I don't spend any money on them.

I think you're "overthinking" this issue.  Just put fuel in your bus, from whatever pump is available, and keep up the routine maintenance, budgeting roughly $1/mile and you'll be fine.

FWIW & HTH. . .

[lostagain]

Oh and BTW, I just remember, quite of bit of fuel is supplied to the American Pacific NW from Edmonton refineries. Also I think fuel is supplied to the North East US from Canadian refineries as well. And the US is now exporting refined fuel from the Gulf coast to many countries around the world. So it is becoming more and more a global market, with a standardization of fuel quality.

JC

[neoneddy]

I do tend to overthink things, sometimes it gets me into trouble.

I'll keep logging records and see if I find any trends.

[luvrbus]

The fuel leaves the refinery 100% pure diesel fuel the Bio is added at the rack,I watched them do it at Sunoco Terminal in Hearne Tx and Western Refinery in Phoenix.
They blend it per a customer specs like Loves,Pilot FJ and others.It is not a science they way they do it with a 6 inch pipe the process is liking a lot when it come to quality control,the bio is supposed to be 75 degrees before blending that doesn't always happen the guy told me at Hearne.
I look for fuel with no more than 5% bio our little 6.5 in the Trek does not like the 20% fuel I drop 2 MPG every time I use it.Circle K and Quick Trips have good fuel just find the right pump         

[neoneddy]

In the great state of MN, looks like we're at B20 http://www.mda.state.mn.us/renewable/biodiesel/aboutbiodiesel.aspx   Maybe that's why I got such good MPG, my tank was mostly winter fuel, last time I filled up before summer was in March.

[buswarrior]

The busnut might be better served choosing fuel via the loyalty program that fits what you do?

Airmiles, charge card discount at the pump, showers, coffee...

For the traveler that avoids RV parks, the FlyingJ/Pilot card accumulates showers. Buy the minimum for a shower, bank it, move on, etc, then use 'em.

And as for the rack at the fuel depot... the wild west comes to mind. If someone screwed up, they send it out a little at a time to hide it. Diesel and gasoline get "accidentally" into each other. Cutting it and sending it to the diesel pumps is the solution. Sometimes in a negotiated deal, sometimes on the sly...

The busnut should purchase fuel from reputable dealers, that turn their fuel over frequently, and get into some loyalty program, either via credit card or supplier program.

Happy coaching!
Buswarrior

[RJ]

For the traveler that avoids RV parks, the FlyingJ/Pilot card accumulates showers. Buy the minimum for a shower, bank it, move on, etc, then use 'em.

If you've got a Flying J/Pilot card thru Good Sam, the folks in the corporate office get real snippy and demanding if you don't pay your balance in full after you get your statement.

So you may get your 6? - 8? per gallon discount at the pump, but hassles from the corporate office may not be worth it.  Not to mention that the "expensive" Chevron across the street may actually be the same price as your "discounted" FJ/P price, and they don't hassle you if your payment is a few sheckles shy.

FWIW & HTH. . .

[chessie4905]

I always heard lower cetane was better. Opposite of octane in gasoline. May be different for electronic engines.

[eagle19952]

I always heard lower cetane was better. Opposite of octane in gasoline. May be different for electronic engines.

Generally, diesel engines operate well with a CN from 48 to 50. Fuels with lower cetane number have longer ignition delays, requiring more time for the fuel combustion process to be completed. Hence, higher speed diesel engines operate more effectively with higher cetane number fuels.

In Europe, diesel cetane numbers were set at a minimum of 38 in 1994 and 40 in 2000. The current[when?] standard for diesel sold in European Union, Iceland, Norway and Switzerland is set in EN 590, with a minimum cetane index of 46 and a minimum cetane number of 51. Premium diesel fuel can have a cetane number as high as 60.[2]

In North America, most states adopt ASTM D975 as their diesel fuel standard and the minimum cetane number is set at 40, with typical values in the 42-45 range.

[luvrbus]

The minimum cetane number for the 2 strokes has been 45 since they were pups