bad gas milage

[tri856]

hey guys i have a 2002 nissan frontier xe v6 crew cab, and as of now i have a the truck lifted 3 inches body lift and a additional 2 inch lift with 15x10 wheels with 32in tires. as of now im average about 50 miles on a quarter tank, is there something wrong with the truck or is it becuase of the lift and wheels? i have had the spark plugs change all the fluids flushed and swapped with new fluids a couple months ago. everybodys been telling me theres something wrong but im not sure. is there anything that i can do to raise the mpg such as performance mod or anything? here is my truck now

[dubie2003]

What is the true mpg? ie. miles driven divided by the amount of gallons to bring it back up?

The lift, wheels, tires, etc.. are not helping. On top of that, the climate and ethanol gas......

How is your knock sensor? How are your driving habits?

[shakedownstreet]

my fuel gage goes down about a quarter after 50 miles. i average around 23 mpg overall (4cyl)

[D22]

When talking MPG, quarter tanks and tank measures mean nothing.

eg.

Car A gets 100 mpg but has a 1 gallon tank
Car B gets 50 mpg but has a 10 gallon tank

Car A would run out of fuel before car B despite car A getting better mileage.

All gas gauges act differently. Even in the same car there are variations (age and whatnot) so your quarter tank wont be the same as someone elses. Also looking at a guage you can only estimate. A minute difference on the guage can be a whole 1/4 gallon of fuel in the tank, you just lost 10 miles.

- Do you drive around town a lot? 0 mph and engine running is bad for mileage. Low speed low gear also reduces mileage.
- 32 inch tires and you loose some gearing advantage (more throttle to keep speed)
- Stoplight grand prix? Bad mileage
- Tow a lot? Bad mileage
- Your foot heavy as mine? Bad mileage

It all adds up and the majority of it would be down to driving habits. Make sure your sparks are gaped properly too.

The way to calculate what you are getting is to:

1 - Fill tank
2 - Note odometer reading
3 - Drive regularly
4 - Fill tank when necessary
5 - Note odometer reading and fuel pumped
6 - Take the distance and divide by fuel pumped (eg. 250 miles/10 gallons = 25 mpg)
7 - Observe result

For accuracy do that several times, will take a while.

[nissanaddicted]

if you are still getting 23 mpg with a lift and big tires on a 4cyl. I'd say its still doing pretty good. I imagine that 2.4 is working pretty hard to turn those big tires.

[jerryp58]

Originally Posted by D22

When talking MPG, quarter tanks and tank measures mean nothing.

The way to calculate what you are getting is to:

1 - Fill tank
2 - Note odometer reading
3 - Drive regularly
4 - Fill tank when necessary
5 - Note odometer reading and fuel pumped
6 - Take the distance and divide by fuel pumped (eg. 250 miles/10 gallons = 25 mpg)
7 - Observe result

For accuracy do that several times, will take a while.

Unless you've done something to adjust your speedometer/odometer, I'd add one more step.

6.1 - multiply mpg in 6 by 1.15

If your stock tires were like mine, 225/70-15, your miles travelled may actually be 15% more than what your odometer is showing because of the increased tire diameter (and therefore, fewer revolutions per mile). I believe the ratio, new-tire-diameter/old-tire-diameter should be the difference.

I would think the larger, heavier tire/wheel combination would decrease mpg, but unless you calculate it like D22 stated and make any necessary adjustment for actual miles travelled, you won't really have a good idea of what your truck is doing.

[zoomzoom]

the shape of a gas tank is asymmetrical. 1/4 tank, 1/2 tank, 3/4 tank means nothing

[Gregg the G]

My 03 CC lwb 4x4 gets an avg. of 14.9 for this year best being 16.8---worst is 13.8 mpg

winter/summer fuels do make a diffenence as does YOUR lift (more air goin under the truck) and the size and weight of your tires.

[Escapehatch]

Originally Posted by jerryp58

Unless you've done something to adjust your speedometer/odometer, I'd add one more step.

6.1 - multiply mpg in 6 by 1.15

If your stock tires were like mine, 225/70-15, your miles travelled may actually be 15% more than what your odometer is showing because of the increased tire diameter (and therefore, fewer revolutions per mile). I believe the ratio, new-tire-diameter/old-tire-diameter should be the difference.

I would think the larger, heavier tire/wheel combination would decrease mpg, but unless you calculate it like D22 stated and make any necessary adjustment for actual miles travelled, you won't really have a good idea of what your truck is doing.

This actually never crossed my mind before. I went ahead and calculated the difference between my stock tires and the 31's I have, turns out I should be multiplying my mileage by a little less than 1.05. If this is accurate, I'm actually getting close to what I should be getting. Although I'm a little curious, how big are your current tires since you're multiplying by a whopping 1.15?

[05Fronty4x]

1.15 is the ratio between the size he mentioned being stock (225/70r15) and 32" tires that tri856 has. It's actually closer to 1.17, but who's counting.