My lie-o-meter seems to read 0.2 tenths higher then my wife's hand calculations. Our 1998 expedition seemed to run about0.2 to 0.3 tenths higher then hand calulating. this is over the last 5 years.

 

Don't forget the whole lawsuit thing about gas stations and temperature corrections. The density of gas when you buy it is not necessarily the density of the gas when you burn it --- so therefore, the hand calculation and the lie-o-meter could both be accurate --- the hand for what you bought, and the lie-o-meter for what you burnt.

 

00 v10 4x4 104000 on it now had it a few months in the hills of cali i get 10-11 mpg have not done enough towing to calculate a tanks worth. just be easy when pressing on the gas there is no need to past half throtle.

 

16 mpg is very possible with the v-10. I have easily reached that on two highway trips since buying mine this past April. Keeping it at 65-70mph on flat to rolling hills. This is with a family of four and luggage.
If you have to get your foot into it or are hauling a lot of gear you can forget it. I routinely get 11-12mpg around town.
All calculations done by hand. My display routinely calculates .02 high.

 

ZBeeble has a good point..I still get my trucker magizines and there is ALOT of talk about hot diesel. When we were still driving team a few years ago nobody had even heard of it... Wonder how long the oil companys have known about it?.......

 

There has been alot of talk about the calibration of standard measures in fuel pumps lately. I believe the standard here in Minnesota is at 60deg. This is the underground temperature so you don't want to fill after that tanker visited at 4:00 on a 95deg. day or worse. Hot fuel sucks your paycheck big time.
You are supposed to get the most for the money asap in the AM. The tank has cooled down and all fuel bubbles/foaming has settled over night. The oil companies know about this and can't lower the calibration on the pumps as this it a regulation standard unit and is tested annually and certified on all pumps. (stickers of state weights & measures board)
Remember: We get more when it gets cold out. Or so the story says.

Regardless , Move over...... , Rich.
BTW - average 12.5mpg highway , 10.5 Towing travel trailer ,11 Mixed (everyday)
2002 Ex 4X4 6.8 V10

 

I have a 2000 4x4 V10 Excursion. I just finished a trip from Columbus, OH to Chicago abd back. On paper I got 15.1 mpg. I didn't reset the meter before I left, but it seems to be pretty consistant at showing .5 mpg more than what I calculate on paper.

 

See my sig for my truck, plus I have 3.73 gears. My truck is my Daily Driver. Going to work is usually a 50-65mph drive, with some stops along the way. I am currently seeing 12.5 to 13mpg.

When I first got the truck, I was running the A/C full blast, taking of like a bat out of hell, and just getting on the truck. I ended up with 9mpg. I don't drive it like it's a Camaro anymore.



I don't have a lie-o-meter, so I do it all by hand. My goal for the truck is to one day hit the 15mpg for my drive to work. I think with some exhaust mods, and other things, I might be able to. Sure, the cost to get it there will out weight the good, but I'd love to say I get 15mpg all the time.

As for towing, and highway driving - nothing to report yet. I only did one jog on the express way for a half tank of gas, mixed with very in-town driving (35mph). It was just over 14.5mpg.

 

i get about 10 to 11mpg in the city, easy on the peddle, and about 15.1mpg on the highway at 72mph@2000rpm. anything past 72mph and 2000rpm my mileage drops off. this is also on flat land which is most of southern nj highways. i also have a few performance mods--see below.

 

I was just reoprting my experiences and opinion. But since you brought it up, you said the OEM meter is making some assumptions and you're right - but when you calculate by hand you're also making some assumptions, like that the pump displayed the correct amount, your speedo is accurate, your truck was nice and level at the time of the fill up, and as ohers mentioned, the gas was cool and bubble free.

When you think about it - @ 44 gals of fuel, if the pump is inaccurate by +/-1%, then your off by almost 1/2 gal (+/- 0.44 to be exact). Now let say that you're getting 12 mpg and you refill after 480 miles, when you calulate you could be off by as much as +/- 0.15 mpg (you should have gotten 40 gallons, but that 1% could put at 39.5 or 40.5, depending on the + or -). Now if you throw in your speedo being +/- 1%, you've just increase the variance and your mileage could be +/- 4.8 from the actual odo.

There are just so many variables that come in to play for both methods, hence the reason the goverment chose the term "Estimated MPG".

So my point was that I felt mine was close enough for me to depend on - but I still recheck it from time to time when were on trips.

 

You're right, Mark. Only thing is that all the variances you refer to are in addition to the assumptions made by the OEM meter. I always eliminate my speedo issue by checking it against at least 30 miles of interstate when I can stay on cruise at a single speed the entire time, and then repeat that on at least 2-3 different sections of interstate to determine my speedo's accuracy ( I know, I know, that also includes assumptions about stop watch accuracy and mile post location accuracy).

Seems like we just can't get away from assumptions!!

Regardless, like I said earlier, I'm glad that your meter seems to be more reliable than most, since it simplifies your ability to track your mileage. Ultimately, I don't even have the option with my truck, so, on a daily basis, I'm stuck with my hand calcs regardless of assumptions.

 

If you know someone with a GPS either vehicle mount or handheld, that would give another avenue of checking you speedo.