I run 91 in both my vehicles. Huge power/mileage difference in the Durango. Noticeable power/mileage difference in the Yota.

 

I'm tracking my MPG very closely...my driving is probably 30% in-town and 70% hwy.

Last fill-ups have been fairly consistent:
19.60
20.33
20.12

 

AND???



Thats good mpg.

 

Last check was 10mpg >.< I realized something though when I was using my GPS. It reads I'm going much faster than what the trucks gauge is reading. I'm accounting this for the larger than stock tires running on stock 4:10 gears. When I'm driving 65, the GPS reads 76mph and slight scales down from there. So the gauge is telling me 10mpg but it's actually more, not sure how to do the calculation to convert but I'm sure it's not more than 15mpg. Anyone know?

 

You have a gauge for mpg??

...my guess is that the same correction factor for your speedometer would apply to your "mpg gauge".

So, take several different indicated speeds from your speedo, and compare them to your GPS readings (try and stabilize the speed for at least 5-10 seconds). For example:

40 mph (speedo) = 50 mph (GPS)
50 mph (speedo) = 60 mph (GPS)
60 mph (speedo) = 70 mph (GPS)

Now, to make a "correction factor", take the average speedo reading and divide it by the average GPS reading:
speedo/GPS = 50/60 = 0.833

...I would then apply this correction factor to your mpg calculations (based on speedo or odometer):

(Indicated mpg) / (correction factor) = corrected mpg
(10 mpg) / (0.833) = 12.00

Note - This assumes a constant difference between indicated and actual speeds throughout the range of indicated speeds...which may or may not be the case.

You collect the data and I'll check it out if you like. I would need a range of indicated speeds and the GPS values (and mpg readings) for each of those.

Cheers,
Dave

PS: Using your numbers above (65 mph = 76 mph from GPS for 10 mpg)...I'd say your actual mpg is 11.69. More data would make for better results though.

 

76/65= 1.169 so your speedometer is 16.9% off.

When you calculate your gas mileage, multiply the result by 1.169 and you'll have your corrected MPG.

 

...umm, yeah...that is a little more straight-forward.

 

I saw you driving the other day BMcEL, you got your topper on right?

 

Thanks for the info on correcting the mpg. Also, I do not have a MPG gauge, I was talking about the speedo vs the GPS. All your numbers make sense and sound about right, alas 12mpg from 10 is still horrendous. I hope these 4:88 gears will change that and some work on the carb. Also worth mentioning, I have a rebuilt (1000 miles) long block from engine world here in Oakland, CA ($800+ core). The guy told me the engines are sent to Mexico and rebuilt there.... cheap labor I assume. They are all machined to tolerance. Could the slightly bigger displacement be causing the engine to run lean on the stock carb not adjusted... resulting in worse fuel economy? I just put some of that carb cleaner in the fuel tank stuff. Truck seems to be noticeably more responsive on the throttle. Any insights would be greatly appreciated. Thanks again!

 

Hah sure do...where at?

 

It was saturday you were getting on 126 and i was coming off of 126, around 430 or so?

 

Ah, right on. I was headed up Australian to see if they opened it back up yet. We should grab a brew and talk Yota some time.

 

I want to talk yota and drink some cold ones. Wonder how long it'd take to drive from California up to Oregon

 

Hell yeah man, im not familiar with Australian? i was comin down from shot gun creek, still pretty sloppy up there haha.

were only about 3 hours from yreka

 

I'm actually flying down there to work out of my Sacramento office and get out of this damn rain next week. Still about 2 hours from San Jose though.

 

Ya I haven't been up Shotgun in a while...are most of the trails still closed off up there? I was up McGowan to go shooting a few weeks ago and it was pretty lame.

 

Yeah Weyerhauser has alot of it gated off. i just went up there to shoot some clay pigeons and stuff. had to move some trees.

 

well next week im off college, spring break \o/ Too bad I'm 33, married, kids, etc... no cancun I guess. I'll actually be heading out that way to folsom to spend a couple days with a buddy and runs some trails he found out there. I'll PM you if this becomes 100% (just the tentative plan right now)

 

Crazy weather here in the valley lately...I was over at my Bend office a few weeks ago and it was nothing but sun. I'd still be living there if the corporate office didn't need me in Springtucky.

Maybe I'll rent a new Tacoma and do a few shakedown runs lol.

 

Yeah no kidding. We need some sunshine. got too much work to do to be doing it in the rain.