My 06 has 2300 miles on it. Been driving 50%-50% city hwy. I have been happy with the MPG and expect a 3 mpg jump somewhere at 7000 to 10000 miles.
Been using Mobil Diesel #2 since I got it. About a week ago I added Power Service (white stuff) 11 oz of it in a full tank (34 gallons). The knocking was a little less ( I like it noisy). But it had a little less "get up and go" , nothing major. I guessed was just getting used to the power. MPG was showing 13.3 and hand calc was 13.6 no problem in city.
Now, last night I just filled it up 27 gal. #2 Diesel Moble same place as always. reset OVHD like always. Now 30 miles later have better power and display spiked up to 22 MPG (ya right) but came down to 15 not the usual 13 mpg. What gives. I figure PS cleaned something up, the diesel supply changed , some sensor is acting goofy or the PS was too much because Mobil has it already. I could be over analizing and should just sit back shup up and dont touch anything.
I thought PS was going to improve mileage while using it not after.

 

Yup overanalizing stuff. Especaly if you are strictly going buy the overhead. I dont care what the bottle says the power service dont do squat for milage. I run it in the winter just for the added protection against gelling but have never seen ANY form of milage diference from running it. As far as the overhead going up 2 mpg, dont waste your time looking at that thing it will drive ya nutz for no good reason. If you are only 30 miles into this tank the diference could simply be that you had a while that you where getting bad milage and now you are getting a little better but there where not enough miles at the better milage to bring up the average to what it was actauly getting. I find that it is REAL easy to drive down the milage on the overhead but 10 times harder to get it back up after improving the milage.

 

I don't trust the overhead much, but it is nice to have. I was just suprised by the additive. I will take your advice I'll monitor temperature & direction & keep my sanity.
I was just suprised after using the additive. Reading the other threads, it appeared that there would be an increase in mileage. I'm not looking for any great MPG I know it's a #7000 truck w/4WD, and will never miss driving an underpowered 'golf cart'.
I was just making sure I wasn't messing something up.
Thanks

 

I use PS all the time and I did see a very small increase in mileage (approx .5-1MPG) also noticed smoother running and a little less smoke WOT. Just my obs and yes don't watch that overhead. I watched it like a hawk on my way to Sturgis this year and was highly upset when I could see the MPG dropping off at a fast rate. Then when I filled up the overhead wasn't even close.

 

I am much happier not whatching MPG. I really enjoy the truck & this forum, it is addicting.

 

Mine is so far off I don't even look at it. Just keep on the compass and outside temperature. Last time I even tried to check the overhead indicated 19.5 mpg but hand calculated was 22 mpg.

MikeyB

 

Guys, I don't trust the mileage if I'm running the TST on anything but 0 or 1 but I use the distance to empty a lot. When it says 0 you had better be within 10 miles towing or 20 miles emply of fuel. The tank holds 125 litres of fuel and I've put 124 in too many times ks

 

to late for me,,I"m already crazy from watching the overhead mpg average