This isn't about summer diesel fuel vs. winter fuel.
Here in Florida, there is no such thing as winter fuel.
I always believed gasoline and diesel was pretty much all the same no matter where you fueled up.
Anyway, here's my story:

I usually fill up at either Racetrac or Shell. Racetrac is the most convenient and at Shell I can get a small discount using my grocery store card.
Racetrac and Shell consistently provide good fuel. Where other places like MurphyUSA, BP, and Speedway have crudded up my fuel filter.
Once I get a bad tank of fuel, I dont go back.

Two days before the arrival of Hurricane Matthew I went to my usual Racetrac but they were completely out of diesel. So instead, I went across the street to Flash Foods.
The hurricane passed and after a week or so of driving I noticed a increase in MPG.
Didn't think much of it and went back to filling up at Racetrac and getting my usual 22-23 MPG.
On a whim, I started going back to Flash Foods and my last three fillups there have yielded 25-26 MPG.

Its hard for me to believe that one fuel source would be better than another. Especially when they are the same price. But nothing else has changed with my CRD.
I have no idea who supplies diesel to Flash Foods or Racetrac.

So what do you think?
Can one fuel station have better fuel than another?
Or is it all in my head?

_________________
U.S. Army Retired

If you're hand calculating mpg you also need to consider:
The accuracy of the pump - is one pump telling you it's putting in more fuel in than the other?
The point the pump shuts off - are they both filling to the same level?
The inclination of the forecourt - is your vehicle sitting level at both pumps?

Do not rule out the possibility even in FL. that different fuel distributors may be getting winter blend diesel while other distributors may still be supplying summer fuel they had on hand ...
Probably depends on their volume usage rate!

_________________
Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount
98 Dodge Cummins 24 Valve

Considering the the Florida Dept of Agriculture and Consumer Affairs puts a sticker on each pump validating that the pumps dispense the correct amount, I should be able to trust that the pumps are accurate.
Also, the vent at the top of my tank leaks. So I know when the tank is full because it starts dripping. I only spill a few ounces. Not enough to significantly effect any calculations.
And yes, I try be sure the vehicle is level.


Its certainly possible but I have never ever noticed a drop in fuel mileage when filling up during winter months. Assuming that winter fuel would cause a drop in fuel mileage.

WWDiesel,
Looks like Flash Foods is primarily a southern thing. And the little bit of research I've done indicates their distributor might be in Waycross GA but I cant be certain.
Maybe you could try a few tanks to confirm?

_________________
U.S. Army Retired

Yes different stations can have better fuel. I actually do better with BP diesel. Look at the pump. They all say the maximum amount of Biodiesel in their fuel. Some have 5%, 10% or 20% maximum. The other variable is the cetane rating. All tanks should list the minimum cetane value on the pump. The higher the better.

I think cetane ratings can vary quite a bit. Depending on your tune though it may or may not have a huge effect. I would imagine maybe a stock tune with relatively late injection timing might benefit more from a higher cetane since it kind of advances the timing in a way. A tune that's running more advanced timing may see less benefit.

_________________
2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs

Cetane is the exact opposite of octane. It acts as a combustion accellerant. Higher cetane ratings are for what were called "high speed diesels" 30+ years ago, when (in the US market) automotive diesels were turning 35-4500 RPM. Your industrial diesels that operate in the 2500 and lower range would detonate like hell if they tried to burn some of the treated fuels the auto diesels are running. For them, lower cetane is better, as there is much more time per combustion cycle for the burn to occur, and much higher BMEP is achieved, producing higher torque, which is what they exist for.

One other possible factor is paraffin content (yes, wax) dissolved, it raises the BTU / volume of the fuel mix, which translated directly into MPG as long as it doesn't gel.

_________________
'06 Lbrty Sprt CRD 150K

Sasquatch
DSS Turbo
CAT-elimntr
Weeks Stg1&2 EGRfix
PV-200
BLING
vent gauges

IDParts
head
cams
rockers
Timing set
ARP studs
eTn1 GX2123 5v GPs

YETI Custom Tune
Flowmaster 8325508
Carter P76611M
GM 12611872
Hayden 2986
GM 15976889
PATC Custom Billet
2010 Ram Hemi Trans
Sonnax 44957
Transgo kit
Cooper 51770

It seems that 40 cetane is the minimum standard for diesel fuel here in the US.
All the pumps around here are marked as having a minimum of 40.
At some truck stops off I-95 the pumps are marked as being B5. (5% biodiesel)

_________________
U.S. Army Retired

Right so if the fuel burns faster it can help put the burn in the meatier part of the power stroke. If you wait to long the piston is falling away to quickly to be effective. This is the same reason they advance timing on tunes. You burn the fuel earlier when the cylinder volume is smaller and the piston is moving slower so you get a higher cylinder pressure which means the force on the crank is greater. You get more power from the same amount of fuel by more effectively applying it.

Its just that the EPA doesnt like it because more cylinder pressure probably means more heat which means more NOX.

_________________
2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs

I have noticed this too but not done much in the way to prove it other than a few tanks of fuel and noting how many mpg I got from them. what led me to experiment with different brands is when the Baltimore area based chain Royal Farms moved in to my area with a few locations. They are known well for their Fried Chicken, yummy btw. when they first moved up to the southern PA market their fuel prices were cheap so I went there. I started to notice that I got less miles out of a tank. almost 10% less than I got from fuel from Rutter's, Sheetz, and Hess which is now Speedway. this was based on summer fuel. winter fuel is always less mpg from anyplace I seen.

_________________
2006 Liberty CRD Limited Deep Beryl Green Metallic Clear coat, Fumoto valve, MH ProVent (removed), GDE Eco tune,
OME 790/948 springs, OME struts, OME N132L shocks, Jeepin by Al A-arms, Hercules Terra Trac AT2 245/75R16
Weeks Stage 1 EGR delete, 5 volt steel glow plugs

Yes fuels are very differant. Some had additives others do not, and things like that.

Some cars handle some fuels better than others.

I drive alot and have company trucks as well as personal trucks to compare with.

I've found my diesel runs smoother on diesel from speedway rather than bp.

Mileage difference varies and it harder to figure exactly becuase of uncontrollable conditions

Sent from my SAMSUNG-SM-G891A using Tapatalk

_________________
Jeepless again.

Wheeling an Isuzu Rodeo on 1 tons
and a Stock Chevy Tracker

I have noticed that Speedway and Sunoco both have a sticker on the pumps that say the fuel has at least 5% Biodiesel. Bio ups the cetaine rating I think.

_________________
2006 Liberty CRD Limited Deep Beryl Green Metallic Clear coat, Fumoto valve, MH ProVent (removed), GDE Eco tune,
OME 790/948 springs, OME struts, OME N132L shocks, Jeepin by Al A-arms, Hercules Terra Trac AT2 245/75R16
Weeks Stage 1 EGR delete, 5 volt steel glow plugs

Way back, before the common rail diesels were available John Kennedy had a station near him in Wisconsin that sold 50 cetane fuel. We were all jealous....

_________________
2006 Liberty CRD - the commuter. GDE Full Tq Eco, Samcos, etecno GPs

2006 GMC Sierra Duramax/Allison - the toy
RIP - 1995 Tahoe 6.5 TD
1990 JD 332, yep, the mower is a diesel too

I used to work for a large oil company, the one with the boat that spilled Alaska Oil.

Diesel fuel is comingled in large tanks at terminals and differnt flagged owners (Sunoco, Chevron) can all be supplied out of the same tank.

Most locations that need winter diesel either add anti gel additives at the transporter loading rack or cut it with kerosene, splash blending in the large tanks. Both adds to the cost at the pump.

Gasoline is similar but the Clean Air Act demands additives to the fuel. Some flags like Exxon and Chevron have their own additive and will sell their branded gasoline only with their own additive. Most others use a generic additive which costs less. Exxon and Chevron will not sell nonbranded gasoline with their own additive. They use the generic additive for non branded gasoline.

Most big refiners retail their own fuel like Shell and Exxon even if they make it in Texas and pipe it all the way to Philadelphia.

But that is not set in stone. Exxon gasoline sold in southern WV is bought from the refinery in Ashland KY and barged up the rivers to terminals that are not owned by Exxon. But the gasoline has the Exxon additive added at those terminals.