I have a 02 X Limited with the V-10. I use Royal Purple engine oil. I noticed I am pretty much getting worse fuel mileage the anyone on this forum. In the city with good driving (engine is never over 2kRPM) the gauge reads 8-9 MPG. On the highway at 75 MPH the gauge reads 12 and it reads 13 - 14 at 60 MPH. Mixed driving of both the Interstate and city gives me about 9.5 actual MPG.

Well that’s worse then most. So why am I getting worse fuel mileage then everyone? I live in North Dakota and we have no hills. Everything is flat. The rear tires are filled to 50 psi and the front is at 45 psi. The air filter is not that used. The tire sizes are stock and I have the 3.73 diffs. Its 4X4.

 

Well, each vehicle is different. Yeah, you might need a tune-up, but first you need to hand calculate your mileage, and stop going by the overhead. That will give you a true reading.

Stewart

 

You also have winter blend gas now that drop avg mileage by about 1mpg. I am from SD and it is the same. You could add 10psi safely to the tires. I have 35s and run 47-48psi. I ran 65 with stock tires. Is your city driving slow with many stops. My city driving has 45-50 mph where in other towns it was slower and mileage dropped.

But, if mileage does not improve in the spring/summer it should be looked at. I have a 2wd and get better mileage than you after 35s and inches of lift.

 

Driving styles is about the biggest difference anybody will every see. Being young i am sure ( cause I did it) you are racing around zoom zooming by the girls and what not, now be honest you know you do sometimes even if a little. If you are one of those people that stay on the gas until the very last minute before hitting the brakes. Do you let the vehicle warm up before you leave in the morning. Do you sit in the drive thru waiting for coffee in the morning, it all adds up to poor fuel milage. The best thing to do is to stay off the throttle, coast to a stop, keep the truck rolling as much as possible, if you play with your computer while you are moving you will see the ways to save and spend fuel milage.

 

A V-10 is a BIG, POWERFUL, engine... and it's pulling a BRICK as far as aerodynamics go (and fyi - don't think they have winter blend for gasoline - just deezle)

BUT, you my be filling up with an ethanol blended fuel or lower btu type gas that isn't as EFFECIENT as the higher quality gas...

but driving style is the biggest variable for sure...

Are you comparing your v-10 fuelage to the deezle mpg ?

and, hate to tell you, your overhead is probably optimistic

 

Like I stated above the engine does not get above 2k rpm. It’s not possible to haul *** and not get over 2k RPM. In fact it’s hard to even keep up with other vehicles without going over 2k. So the driving style is as calm as a driving style can be. I don’t use fuel containing ethanol. I only fill up with 87 octane from BP, and nothing else. My city driving is 25 - 40 MPH. There is some stops but nothing extreme. I don’t idle the vehicle more then a couple of minutes in the drive through. Drive through here are always short. I let the vehicle warm up about two minutes in the morning but its parked in a garage. 50 PSI is the max safe pressure of the tires for they are only load range C tires so I cant go higher. The listed MPG values are calculated from the overhead meter.

 

SPL, I get 11 to 12 in the city and 14 to 15 mayb almost 16 (depends on how slow i go) on the highway in the summer. In the winter the milage always jumps down. Im getting the same as you right now.


Miles per tank,

Summer: 460-480, depends on what RPM's im at when im accelerating on take offs.

Winter: 390-410,depends on if the wheels spin when accelerating or if i do
doughnuts in the parking lot.


Quote "You also have winter blend gas now that drop avg mileage by about 1mpg."

I think igotoneforya for you is right about the winter blend.

 

Why would it matter if its winter or not? I know that driving in the snow and spinning out drags you down, but there is no snow or ice here, its just cold. And from what I was told, the colder the air the more horsepower you get.

 

The v-10 like to rev, you get better fuel milage if you run it on the 2-2.5 rpm range as that is where the torque band is still in the usable range, keeping the v-10 low rev actually does more harm then good. In the winter blends of fuel they add more of something to it to help with lines freezing similar to gas line anti freeze. In colder denser air the fuel will not atomize as well and therfore more fuel will be stuffed into the engine without burning, there is a whole lot of reasons for each and every vehicle's MPG. I find that some brands of fuel will make far worse fuel milage. Up here in canada the worst fuel around in any vehicle i have driven was Esso i like sunoco the best then shell. So try different fuels out try changinr your spark plugs...do iy corectly... gap them right and see how that does.

 

I don't think you can find gasoline without ethanol in it. MTBE was outlawed last year and I haven't heard of another oxygenate besides 10% ethanol. Just because the pump doesn't say so, doesn't mean it's not blended in.

Taking it 'easy' on my V10, I only got 8.5-9.5 in the city and 14- 15.5 on the highway. Mileage claims are highly subjective. The V10 is a gas hog.

You really ought to put a set of 'E's in the budget. At least before you load it up.

Take Care

 

BP has been rated as the best fuel in the world by pretty much every company that reviews fuel. So I cant get anything better. I am thinking of changing out to the Bosch premium spark plugs for my X. They helped increase HP in my Jeep so I suspect they will do the same. However I looked on the engine and could not find the plugs? Are they under the orange things on the side of the engine? Or are the orange things the injectors? I didn’t look very well.

 

You're not the only one. I told you what to expect in the Excursion before you bought it. I also mentioned you will never see the figures most people post here on V-10 gasoline engines. I know I don't.

 

I have a 2000 XLT 7.3 PS Diesel---I get only 14MPG. I am a maintenance addict --so it that's not it.I thought it had to be my driving.
WELL:
My brother drives like a *****cat and he took it for a week down to FL in the Fall--all highway driving--he averaged 14.5MPG.

Sounds like I need to have something checked out--what do you think and what?
Do you think I ought to install a chip?
Thanks for your thoughts
Tom

 

My wife drives our Ex, and with tons of idling for drop off / pick up of kiddos, the "lie-o-meter" usually reads in the low 10s. We see occasional high 9s.

That said, I entered all of our data in an Excel spreadsheet (we write down the miles and gallons at each fillup) and the gauge is indeed optimistic. The spreadsheet shows we have only gone over 10mpg maybe a dozen times in the last 20k miles that we've had the truck.

Yes it hurts when gas is $3 a gal. You better have made darn sure you really want this beast. The Suburban 1/2 ton we traded in got between 14-15mpg (in Excel) so the fuel penalty for the Ex is indeed large. We had no choice for towing our travel trailer though - the Sub had no guts and was very unstable compared to the Ex.

Doug

 

You must realize also that when it's cold and your motor is also cold, the computer must richen the mixture quite a bit until things warm up. We dont have a winter mix fuel down here(normally no snow either), and I know we loose a little MPG due to just the cold weather.