I'm sorry but I have to ask about my MPG

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

I disagree with mileage increasing in hilly terrain. I live in a hilly area, and I only average about 11-12mpg mixed driving; however when I'm on the highway, I'm usually over 15mpg, sometimes over 17. That's with 33's, adjusting for the tires at 6%.

I attribute the low city mileage due to our hilly terrain. There cannot be a total fuel cutoff on deceleration due to the fact that if there was, the engine would choke out.
 
how do you keep the rear bumper from flapping like a flag at that speed? Those must be 100mph Zip Ties :) :)
 
wait for it..... wait ......

there it is......
DSC00702.JPG



:D
 
larryt said:
If you have a GPS, sync up the trip odometers on your GPS and on your truck and figure out what percentage your odometer is off. It may only be a few more percentage points, but at least you will have a more accurate reading when doing math at the pump. I have 295/75-16s and mine is 8.75% off.
Click to expand...
The GPS correction is pretty important because you can't really trust the MFG. stated diameter. I measured a correction factor of 1.062. This is for the 285/75 R 16.
 
arbetrader said:
I disagree with mileage increasing in hilly terrain. I live in a hilly area, and I only average about 11-12mpg mixed driving; however when I'm on the highway, I'm usually over 15mpg, sometimes over 17. That's with 33's, adjusting for the tires at 6%.

I attribute the low city mileage due to our hilly terrain. There cannot be a total fuel cutoff on deceleration due to the fact that if there was, the engine would choke out.
Click to expand...

Most vehicles now have a complete fuel cutoff on deceleration. It's actually in the FSM. You can also verify this with a OBDII gauge (in fact I think Nick may have posted a YouTube of this a year or so ago). Closed throttle and RPM > 1150 = zero fuel. While the engine isn't providing any power, it is still being turned by the drive train so the effect is transparent to the user. Most people tend to feather the gas which negates the benefits. Either apply power or completely off, but don't coast with your foot on it.
 
GranolaJoe said:
Good discussion.
Okay so I went for a drive this evening....
Truck stated 18.0 miles - gps stated 18.8
Truck at 65 mph - gps said 67.5

Who's the math genius?
Click to expand...

No genius required. 18.8/18.0 = 1.0444.

Personally, I'd take it for a longer validation run as a small GPS error could be significant in 20 miles.
 
I get the same range as you stated, 9-12 with 295/65/20 with armor, gears, and a roof rack no matter what i do. A resent trip all interstate with the cruise set on flat land yielded 14.5, that was the best i ever remember. When I was stock except for tires I didn't do much better. I write it off as the price to ride in a landcruiser.
 
Yeah, I guess you're right. I thought someone was suggesting more was involved (maybe that was regarding tire size). So, obviously you multiple that by recorded MPG from odometer?
Yes, I plan to look at it again on a longer trip. Thank you!
 
As I metioned in the origianl post, I was getting 9-12. Today I did (had done) the 90k service. On my little test drive for the odometer/gps reading, my nav computer calculated a little over 15 mpg - the best I've seen in my short 4 weeks of ownership. Could it be that something done in that service had that much of an impact? I've only driven 18 miles since I picked it up, so time will tell but initially, it's seems better.
I had belts, water pump, antifreeze, lube, thermostat, idler arms/pulley done. They didn't really want to do the thermostat, but from reading here, I wanted it done. Is it possible the thermostat could make that difference? Again, 18 miles is not enough to tell yet, but the early 'data' looks good.
 
Get a ScanGaugeII and calibrate it. That's the only mod I've bought for a car that actually improved gas mileage.

The only time I ever 9-12 is during LA Rush Hour traffic. Have you changed the Diff oil since buying it?

I'm running Mobil1 Synthetic 75w90 in all the diffs and Mobil1 Synethic [STRIKE]0w20[/STRIKE] 0w30 engine oil. Also have a K&N drop in filter, same tires as you. Not sure if any of that actually helped mpg but I get 15-18 on the highway, 14-15 mixed, 11-14 city.
 
Last edited:
KlausVanWinkle said:
Get a ScanGaugeII and calibrate it. That's the only mod I've bought for a car that actually improved gas mileage.

The only time I ever 9-12 is during LA Rush Hour traffic. Have you changed the Diff oil since buying it?

I'm running Mobil1 Synthetic 75w90 in all the diffs and Mobil1 Synethic 0w20 engine oil. Also have a K&N drop in filter, same tires as you. Not sure if any of that actually helped mpg but I get 15-18 on the highway, 14-15 mixed, 11-14 city.
Click to expand...

Very tempting Klaus, I'm looking at them now. Thinking about changing all the fluids (not necessarily for gas mileage) as well - just seems like a daunting task. But, I'm sure if I read up about it here that it would be relatively smooth.
 
It's easier than changing the engine oil. You just need oil, new crush washers and a $7 fluid pump to pump the oil into the diffs (because you can't pour it because of the angle). <$100 total.

Amazon.com: FLUID TRANSFER PUMP-4CC: Automotive


If the parts are the same as a 2000 then:

Toyota Parts Number:
12157-10010 (x4)
90430-18008 (x2)

T-Case 1.4q Synthetic Gear Oil GL-5 75W-90
F-Diff 1.8q of 80w-90 Hypoid gear oil
R-Diff 3.5q of 80w-90 Hypoid gear oil

75w90 is fine.


How to:

https://forum.ih8mud.com/100-series-cruisers/31824-rear-differential-fluid-change.html
https://forum.ih8mud.com/100-series-cruisers/31890-front-differential-fluild-change.html

Center is just like the front I think.
 
Okay, so I've had a Scanguage now for a couple of weeks. The main main motivation was to try to get to the bottom of my poor MPG's. The best MPG's I've seen so far is in the low 14's on a highway trip (wind aided). I've definately driven very light on the gas - lighter than I ever have but cannot get better than that. Anything else on the Scanguage I can look for? Otherwise, where should I start looking - seems to me something is off somewhere.
 
What's your GPH at idle after the engine's warmed up with AC off? Have you already calibrated the Scan gauge by filling up, using a tank of gas, filling up at the same pump and seeing how much you really used vs how much the scan gauge estimated?

I usually keep the TPS reading on screen so I can see how hard i'm pressing the gas pedal.
 
GranolaJoe said:
Okay, so I've had a Scanguage now for a couple of weeks. The main main motivation was to try to get to the bottom of my poor MPG's. The best MPG's I've seen so far is in the low 14's on a highway trip (wind aided). I've definately driven very light on the gas - lighter than I ever have but cannot get better than that. Anything else on the Scanguage I can look for? Otherwise, where should I start looking - seems to me something is off somewhere.
Click to expand...

Nothing is off....the most i've ever gotten on the highway is 14 mpg. Ever...

10-11 in town, MAX.
 
KlausVanWinkle said:
What's your GPH at idle after the engine's warmed up with AC off? Have you already calibrated the Scan gauge by filling up, using a tank of gas, filling up at the same pump and seeing how much you really used vs how much the scan gauge estimated?

I usually keep the TPS reading on screen so I can see how hard i'm pressing the gas pedal.
Click to expand...

600-700. Yes, I've done the calibration.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom