Horriable Gas Mileage affter trip?!?!

[Cable810]

3.42 GU6

[bartonmd]

Alright filled up and it took 10.813 and I drove 214.2 Miles according to OD. So what's the math that will get my actual miles driven ?

miles per gallon = miles/gallon = 214.2/10.813 = 19.8mpg if you odo is correct.

If you actually meant to ask what the odometer error is, you can do a percent difference calculation.

(29.5" - 33")/29.5" = 12% difference low, so take your 19.8mpg and multiply it by 1.12 = 22.1mpg if you have 33" tires.

You're sure your vehicle was at the same angle and you filled not only until it clicked once, but until it was FULL?

Mike

ETA, looked at James' post and saw you not only have different size tires, but also went from 3.42 to 4.10, so % difference between (3.42 - 4.10)/3.42 = 20% So multiply 22.1mpg by 0.80 = 17.68mpg

[HARDTRAILZ]

He also changed gearing and went up in tire size, so the error is not that simple.

[jonbo2002]

Alright filled up and it took 10.813 and I drove 214.2 Miles according to OD. So what's the math that will get my actual miles driven ?

miles per gallon = miles/gallon = 214.2/10.813 = 19.8mpg if you odo is correct.

If you actually meant to ask what the odometer error is, you can do a percent difference calculation.

(29.5" - 33")/29.5" = 12% difference low, so take your 19.8mpg and multiply it by 1.12 = 22.1mpg if you have 33" tires.

You're sure your vehicle was at the same angle and you filled not only until it clicked once, but until it was FULL?

Mike

that and did you fill it completely before you reset your trip?

oh yea and gotta figure out the difference with the gearing change like Kyle said

[bartonmd]

He also changed gearing and went up in tire size, so the error is not that simple.

Yeah, I saw that after I saw James' post, so edited my post.

17mpg aint bad, IMO.

Mike

[HARDTRAILZ]

Those tires are maybe 31.6 not 33...

[HARDTRAILZ]

16.97.... Not bad at all.

[bartonmd]

Oh, I didn't see them in the thread and was guessing 33" tires.

Mike

[HARDTRAILZ]

265-70-17 He posted in the posted post with miles and gallons.

[bartonmd]

Oh, I didn't catch it.

Almost 17mpg with bigger than stock tires and 4.10 gears, though... nothing wrong with that mileage.

Mike

[HARDTRAILZ]

Not at all....

I figured you missed it with all the other stuff going on on your vacation

[Cable810]

Ok I filled up completely the last time and reset everything. When it clicks I'll keep going till I start to see some gas coming out. Wow I got worried over nothing

The formula that Mike posted is the formula to calculate MPG with the oversized tires and different gears?

[bartonmd]

Yes, except you replace the 33" tire size with whatever yours are. The gear ratio calculation is still correct though.

Mike

[Cable810]

Ok thanks

[Cable810]

Sitting here calculating Mpgs after Drummond. Wanting to make sure I'm getting this right.
(29.5-31.7)/29.5 =0.07 which is 7%? So then 1.07 x mpg = XYmpg x .80 = final Mpg?

[DirtyBacon04]

ETA, looked at James' post and saw you not only have different size tires, but also went from 3.42 to 4.10, so % difference between (3.42 - 4.10)/3.42 = 20% So multiply 22.1mpg by 0.80 = 17.68mpg

I'm not very good at math... where did the 0.80 come from? Just the difference from the 20% ?

[djthumper]

Sitting here calculating Mpgs after Drummond. Wanting to make sure I'm getting this right.
(29.5-31.7)/29.5 =0.07 which is 7%? So then 1.07 x mpg = XYmpg x .80 = final Mpg?

yep that should be correct.