Anyone seeing a drop in mileage with winter grade fuel? I just went on a trip and did my mileage. In september I got 22.0mpg on a freeway run that included jammed 10mph traffic, and a two lane highway (varying speed). Today I got 21.6mpg in perfect conditions. 72mph with the cruise set the whole way. Juice on level 2. I wonder why Summer grade yeilds better mileage...anyone know?
I don't know exactly what they do for winter fuel now with the ULSD, but winter fuel used to be Diesel #1 & #2 mixed. #1 flows better in lower temps. The problem though is #1 does not have as much energy potential per gallon as #2 does so it lowers the MPG since the mix now yields less power. #1 also offers less lubricity so you need to be a little more generous with the additives during the winter fuel season. Harley
4/10's is enough for human error... i mean you couldn't have driven the EXACT same path at the EXACT same speed with the wind factor, varying speeds all being the same... i think you are being anal...
I'm comparing the two trips. They weren't even the same stretch of highway. What I meant was that my trip back in Sept. on summer grade was a much harder drive with stop and go freeway traffic and varying speed. Yesterday while having winter grade, I get less in perfect conditions with NO wind, no traffic, and steady speed.
right, but i guarantee its not the fuel... you have to consider viscosity in the diffs, tranny, and t-case... air pressure is probably lower since it has gotten cold, the air temp is colder therefore more dense, therefore "harder" to drive through...
I would bet money its the fuel. Between the switch to Winter blend and ULSD it would not surprise me in the least. My mileage has dropped significantly. Like to the tune of 2mpg on the same trips. Fluids viscosity is not going to suck 2mpg out of my truck IMO. John
but rjf says that fluid change can increase mileage, so if it is thicker from the cold, how can that not work in the other direction by making it decrease mileage...
If you add a little Baby oil in your fuel it will help off set the differance in MPG some where in the ballpark of 1oz per 10 gal of fuel (works on gasoline too).
colder air in the winter would give you better fuel enconomy and keep you engine running cooler therefore a bit more fuel efficent.The reason for winter fuel not giving better or the same fuel economy is more likely due to how it is produced also is the fuel coming from the same station year round I have noticed sometimes going to a diffrent station you seem to get more "trash" and there for worse fuel economy.Just my .02
Mmm... in the engine and trans the viscosity is going to be nearly the same regardless of season. There is just too much heat generation there for the oil to not reach it's thinest viscosity. Now the tranfer case and especially rear differential could be another story. I honestly don't know how much heat is generated there. But, likely in my weather there isn't much difference. I was traveling in 55* weather, pretty warm. I would definantly say that the gear oil in the diffs could want to stay thicker in sub zero weather. My mileage drop is likely because of winter grade. I'm pretty sure I was running ULSD in Sept. too.
55 would be cold enought to really affect anything as far as the fluids go since the road will be a bit hotter and that will have a bigger afect.
It's the fuel guys.. winter grade fuel is blended with more kerosene, to funtion as an anti - gel. the problem is, kerosene has less thermal energy than neat diesel, so your overall btu's are down, leading to the mileage drop.. you see the same thing happen with biodiesel and ethanol blend gasoline. And yep, ULSD is nearly a #1 fuel when they are done refining it from #2, so you get a mileage penalty there too. Tom
Wheee.. more kerosene.. that'll lower the btu's even more..and increase particulate emissions, and leave more carbon deposits.. talk about defeating the purpose..
I use P/S at every fuel up and i it works great for me. It says that it ups the cetane levels and gives you a better burn rte on the bottle cleans injectors boost power . it also says 50/50 blend wich is #1 and #2.what do you have that does the same and does not cost a lot? Weeee
Well Iam UP In NH for the winter and so happen's I Deliver Bulk Fuel. and the fuel is most defently your or I should say Are Prob. the 50/50 mix robs the pwr and mpg. I use power Service all the times even home in FL. And it works I dont care what some people say .so hope this helps F/P
Hi FullPull: Try this with your power service..take an empty pop can, turn it upside down, and pour some power service in the bottom of the can, where those numbers are printed.. (do this outside of course).. if p/s is an injector cleaner, its detergents ought to clean off those numbers, right? that ink is similar to carbon build up, so you can see if p/s cleans anything or not.. then, try and light the p/s with a lighter.. you'll be there awhile, but when it catches, see all the black nasty smoke it emits.. don't breathe it, because it's carcinogenic, but pay attention to what's left over when it's done burning.. that's what's left in your combustion chamber..yuk.. You can do the same thing and get similar results with howes, or schaeffers, or any other petroleum waste additive...All I'm saying is that cheap products are cheap for a reason.. As for what I have, click on the links in my sig for the whole story - if what I have seems of value to you, PM me and we'll talk. Tom
