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So I knew and didn't expect to get good mpg after adding 305/70r16s the spare to the roof of it creating drag, and the 2.5" lift. But I thought it would be better then 7 miles per gallon haha just seeing what every else is getting with there lifted/big tired Xterra. I did a short calculation: I reset my trip when my gas needle was exactly at full, then took note of the mileage when it was exactly at 3/4 tank. Which was 40 miles, if the tank size is 21 gallon that would mean a 1/4 tank is 5.25 gallons so then you do 40 divided by 5.25 which gives you 7.6 mpg. Now someone please let me know if my math is wrong and I'll admit to being an idiot. Just want to see what everyone else's mpg is.
 

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Your measuring technique needs improvement. Use your GPS for more accurate mileage readings, and measure actual fuel used by recording amount in gals. Start over, fill tank and drive until the tank is near empty, then refill. Record actual fuel used and divide by milage recorded by your gps which is much more accurate than your odo since your tires are bigger. that's unless you've had the dealer re-calibration.
 

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So I knew and didn't expect to get good mpg after adding 305/70r16s the spare to the roof of it creating drag, and the 2.5" lift. But I thought it would be better then 7 miles per gallon haha just seeing what every else is getting with there lifted/big tired Xterra. I did a short calculation: I reset my trip when my gas needle was exactly at full, then took note of the mileage when it was exactly at 3/4 tank. Which was 40 miles, if the tank size is 21 gallon that would mean a 1/4 tank is 5.25 gallons so then you do 40 divided by 5.25 which gives you 7.6 mpg. Now someone please let me know if my math is wrong and I'll admit to being an idiot. Just want to see what everyone else's mpg is.
The gas gauge is not sensitive enough to use that way.

Even one fillup is not great, because the pump might click off at a different fill point.

To get a real idea, you would account for these differences by starting that odometer push/reset on a full tank. Write down the rig's mileage.

Drive at highway speed, and compare your gps speed to your speedometer speed. The larger tires make it look like you are going slower than you really are...so if only looking at the dash speedometer, you will be driving faster than you think you are...and using more gas.

Your odometer is off by the same amount.

So, if only looking at the dash, you are speeding and going more miles than you thought. That will make you burn more gas due to speeding, and, when you look at your miles, it might say you went 200 miles, but you went further.

Drive slower, to make the GPS speed be the speed you wanted. (if no GPS, you can use mile markers and a watch, etc)


When you fill up again, DON'T reset, just write down how many gallons were added, and the miles.

Do that about 5 times or more.

Add up how many gallons took you how many miles.

Correct for odo and speedo error.

Calculate the miles per gallon.

THAT's your miles per gallon.

>:D


(And the tire up there can cost 1-3 mpg all by itself, its why I took mine down, I got tired of paying rent on that space every time I filled up.)
 
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