mileage report

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Chris Sandstorm FJ

Chris Sandstorm FJ

10 Year 15 Year
Joined
Jul 23, 2008
Threads
25
Messages
400
Location
Denver, CO
Hey I am curious what others are getting right now for gas mileage, with a similar build and various years/tires sizes...

I have an '01 4 speed tranny with 255/85/16s, bumpers, winch, alum/steel skids, sliders, lift, roof rack, single drawer and fridge. I also have the DT headers, wonder if that makes a difference also.

I just checked and with tire conversion I am getting 13.2 in the city. I thought that was not really that bad, considering what I am hauling around. Any of you math majors have a clue what that would translate to hwy?

Obviously a 5 speed would fare better on the highway. Just curious what you all are seeing with 285 33s and 34, 35s in similar builds.

Also, I am thinking of having Midas cut off the resonator, wonder if that might help just a touch on mileage.

Thanks
 
13.5-14.5 mixed driving (lots of interstate but depending on time of day it's stop and go). 295/75/16 toyo ATs . Rear bumper (no swing outs) and sliders. 13.2 sounds about right to me.
 
2001 with 141k, Tundra 275/65-18s, converted to stock size I have had ~13.1 mpg since we got it 3500 miles ago, but that includes some really awful 10-12ish tanks pulling our tent trailer through the mountains, most of the miles are in town. Last half dozen tanks have all worked out to high 13's around town.

John
 
I'm curious... I've read here and there about people doing these calculations. The OP stated "I just checked and with tire conversion I am getting..." Can someone here clarify how to do the math with "tire conversion"? The way i do it is to let the GPS calculate the mileage and when i go to the gas station, take that mileage and divide it by how many gallons it takes for me to fill it back up. Of course i have to zero the mileage on the gps on the first fillup. Is there any other accurate way to do this?
 
That is how I do it also, zero mileage at fill up, drive it, fill up and divide miles by gallons to fill it back up.

Nakman posted this up on our RS club forum, where I asked the same question.

"Chris are you compensating for tires in your calculation? I believe your factor should be right around 4%, so (odo miles *1.04)/gallons=MPG"
 
3D FJ said:
I'm curious... I've read here and there about people doing these calculations. The OP stated "I just checked and with tire conversion I am getting..." Can someone here clarify how to do the math with "tire conversion"? The way i do it is to let the GPS calculate the mileage and when i go to the gas station, take that mileage and divide it by how many gallons it takes for me to fill it back up. Of course i have to zero the mileage on the gps on the first fillup. Is there any other accurate way to do this?
Click to expand...

Chris Sandstorm FJ said:
That is how I do it also, zero mileage at fill up, drive it, fill up and divide miles by gallons to fill it back up.

Nakman posted this up on our RS club forum, where I asked the same question.

"Chris are you compensating for tires in your calculation? I believe your factor should be right around 4%, so (odo miles *1.04)/gallons=MPG"
Click to expand...

When someone talks about conversion, it is typically thought about the tire size

You basically take the stock tire size and use the difference with what you are running to compensate for the speedometer being off. If you have corrected the speedometer, then know correction is required

say a stock tire is 31" and you are running 33" tires

33/31 = 1.065. That would be the factor you use for the conversion. Or effectively the speedometer/odomter is 6.5% off

To do the conversion, if your odometer says 200 miles at fill up, you would take 220 X 1.065 = 213 miles. Meaning you really traveled 213 miles rather than the 200 miles shown on your odometer

You then take the 213 miles traveled and divide it by the fuel you just filled up with and end up with the "corrected" MPG. This is what people typically mean when they mention conversion

The speedometer and odometer calculates revolutions and the built in calculation uses the stock tire size. Running larger tires provide a greater distance per a single revolution than a stock tire

This is also important to know for speed traps

If your speedometer says 60MPH and your in a 60 MPH zone, it is important to know you are really going ~64MPH. Typically not an issue unless you are one of those who feels it is OK to drive 5MPH over as they don't typically ticket there. You would really be driving 9 MPH over based on the conversion in a 60MPH zone

I think actual new stock tire size is 31.2". I run a 33.6" tire so my factor is 1.077 or effectively the speedometer is 7.7% off

Now if you regear, then this all goes out the window and you have to consider the gear change impacts
 
2006 model LC
Stock tire height nitto grapplers on stock 18 inch wheels
No other mods besides an OME lift of some type...as yet undetermined

Speedo seems to be accurate compared to GPS speed


Did a recent 1000 mile trip on my newly purchased 100 with 100,000 miles on it....

Wasn't stoked about the mileage observed but it was better than my FJ62 got...


On the highway only sections of the trip, I got 15.3 mpg, averaging 75 mph plus, as calculated by miles driven / gallons replaced to a full tank.

On mixed driving, around 13.3.


I am hoping that running some seafoam in the tank and spraying some and cleaning the throttle body will help the slightly rough idle in gear at 600 rpm and help clean the injectors a bit and bump up the fuel mileage a little.


As a side note, when I got 15.3mpg, my nav unit read 14.6mpg avg.; when I calculated 13.3, it said 12.9.
 
Last edited:
There is waaay too much math in here for me. I fill up when that orangey-red needle gets down by the big "E". It seems like that doesn't take very long to happen. I'm guessing I get around 12.

How close do you think the NAV display is for calculating MPGs? Mine usually reads about 11-12 on the highway and 6-10 offroad.
 
3D FJ said:
I'm curious... I've read here and there about people doing these calculations. The OP stated "I just checked and with tire conversion I am getting..." Can someone here clarify how to do the math with "tire conversion"? The way i do it is to let the GPS calculate the mileage and when i go to the gas station, take that mileage and divide it by how many gallons it takes for me to fill it back up. Of course i have to zero the mileage on the gps on the first fillup. Is there any other accurate way to do this?
Click to expand...

I used the revs/mile off Tirerack to estimate for mine for the Tundra BFGs and what the website pulled up for OEM (Michelin's), I haven't checked the distance by GPS yet, maybe I'll do that next time we do a road trip, but I expect my indicated mileage to go up now that I have smaller than OEM winter tires on.
 
Just a quick plug for ethanol free gas- running a tank of 91 currently as I got it for just a hare over premium gas price and hundy seems to love it.... Getting close to 16.7 in mixed vs 15 normally w ethanol containing fuel
 
paflytyer said:
There is waaay too much math in here for me. I fill up when that orangey-red needle gets down by the big "E". It seems like that doesn't take very long to happen. I'm guessing I get around 12.

How close do you think the NAV display is for calculating MPGs? Mine usually reads about 11-12 on the highway and 6-10 offr oad.
Click to expand...

If you are running 35's, then what you get is 12% higher than shown on the nav display

Don't they teach Marines how to count when your throwing hand grenades (one Mississippi . . two Mississippi ..)
 
Romer said:
If you are running 35's, then what you get is 12% higher than shown on the nav display

Don't they teach Marines how to count when your throwing hand grenades (one Mississippi . . two Mississippi ..)
Click to expand...

I took math for Marines almost 20 years ago. I took spelling too. Neither helped. Throwing hand grenades is for the Army..... the only math I needed was how far left should I aim if a dead center shot hit to the right? And the 10,000+ numbers a day I say when controlling your flight in and out of the 3rd busiest airport in the country.

Your next DC flight is delayed due to air traffic. ;)

So, I'm getting around 12.3-13.4 MPGs. Not bad.
 
Last edited:
paflytyer said:
I took math for Marines almost 20 years ago. I took spelling too. Neither helped. Throwing hand grenades is for the Army..... the only math I needed was how far left should I aim if a dead center shot hit to the right? And the 10,000+ numbers a day I say when controlling your flight in and out of the 3rd busiest airport in the country.

Your next DC flight is delayed due to air traffic. ;)

So, I'm getting around 12.3-13.4 MPGs. Not bad.
Click to expand...

Semper Fi I learned my USMC math 45 years ago :) damn I'm getting old, helps me ID with my 100 series.
 
paflytyer said:
I took math for Marines almost 20 years ago. I took spelling too. Neither helped. Throwing hand grenades is for the Army..... the only math I needed was how far left should I aim if a dead center shot hit to the right? And the 10,000+ numbers a day I say when controlling your flight in and out of the 3rd busiest airport in the country.

Your next DC flight is delayed due to air traffic. ;)

So, I'm getting around 12.3-13.4 MPGs. Not bad.
Click to expand...

That is not too bad. but 6-10 off road is kinda dismal, was that Ouray or Moab??

I was jealous of your tires at the meeting but not your mileage... I may try a 17 wheel next and a 34inch tire, with a width of 12" or under, if they are made.
 
Last Friday, I attained 16.31 MPG's driving a total of 326 miles going between Knoxville, TN and Asheville. NC. This is far and away the best mileage I have observed since purchasing last April. No doubt this was greatly aided by relatively low speed limits going through Great Smokey Mountain N.P and Pisgah NF and much cooler temperatures than experienced in SW Florida.
 
'00 LX with 285/75/16 BF-AT. Corrected for tire circumference.

- 16 mpg driving a long stretch of 1600 miles on mostly highway going 65-70.

- 10 mpg with a 8x16 dual axle landscaping trailer (load on trailer did not seem to matter), Highway driving only as well.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom