2wd and 4wd mpg

Hi guys, when I started shopping the tacomas I was looking for best mpg(2.7 2wd base) By buying the truck I told myself I would lift it and get big tires on it and put a lock, that way ill have the most fuel efficient capable truck tacoma. After these modification I noticed the drop in mpg. I'm really wondering If a 4wd would have got me a better MPG than I have now. Some say its mainly because of my lift (2.75 front,1.75 back). but the thing is the I'm now at the same height as the 4wds with the lift and with a similar tire size to. I'm starting to think that the 4wds are probably made to have the best mpg and tested by professionals. I have three sets of tires at home: 265/275/r16 , 215,65/15(stock) and 235/270/r15. I'm maybe thinking of switching to a 4wd I would just get mags on it and it would have the look, and would be already lifted. My main concern is the mpg but don't want 15inch wheels with low truck. thanks

 

My 2.7 4x4 AC with a 3" lift gets 24 MPGs on hilly hwy with summer gas on stock 245/75/16 Dungflops. When I put my 33.3" 255/85/16 BFG KM2s I get from -2 to +2 MPGs hwy compared to stock depending on hilly or flat. Now that I added sliders & a full set of skids my MPGs have probably dropped some.

 

MPG drop is due more to the big tires rather than the lift.

 

If you go 4WD you'll be stuck with 4.10 gears or higher. Your 5 lug is lower than that for mileage reasons.

The ideal 4WD mpg frankenstein would be to swap the 3.73 diffs from a V6 into a 2.7L truck but that would probably never pay for itself.

Don't forget to compensate for tire diameter changes when calculating your mileage. Bigger tires will make the odometer read deceptively low.

 

Ok thanks for the advice, and yes i take the odometer changes into consideration when calculating mpgs. By having a similar tire size and height as a 4x4, would i have better mpg on a 4x4?

 

NO

Are you trying to justify going 4x4?

 

4x4 means extra weight and spinning two extra axles. It's always a loss in efficiency. That's why PreRunner trucks typically beat the mileage of the 4x4s by about 2 mpg even though they have the same gearing, suspension, and tire sizes.

Highway tires give good mileage. Off road tires definitely less so. No mod in this world will change the laws of physics on that one.

 

Say you took a 2wd 2.7 and got 29 mpg (Guessing) model, the mpg likely goes down if: it got heavier tires, more tready, taller tires, or Add a lift. That doesn't mean a 2wd modded up to a prerunner like setup will get crappy mpg, it could drop 2-5 mpg. I wouldn't be surprised if you did a re-gear, say 4:10 or so, you might recover some mpg. My reg cab 4wd gets 25mpg at 65mph if it helps

 

You guys make me laugh.

Always great coming here and reading about the comic book approach to MPG.


Keep it coming...especially all you "Senior Members" who know it all

 

Nice contribution.

 

Noone knows it , especially you appointing what you think, people think.
Grow headcase, ,if you have no answer just say so, we'll help you out too.

Since there is no fixed values to mpg gain or loss , cookie cutter it is.

 

Gonna dissect this farther, based on the smaller and larger set of tires , you are 14% off on your mpg/odometer. Math is 215/25.4 =xx
take that value and multiply by .75 for sidewall... then x2 and add 15(rim).
25.4 is simply mm to 1" conversion. you are likely missing mpg that's simply there. Do the same for the 265 tires. in the end its a 27.6" tire vs a 31.6" tire with some rounding. I don't know stock 2wd ring gear, but if you do, multiply that by 1.14 and you get a corrected ring size ... or go up more yet.

You said " ...that 4wds are made to have the best mpg" As someone said the added driveline and drag, and component weight actually lower mpg.

I like you idea of just building up a 2wd, with a locker or lsd , you have a lighter truck and no chance to bind the drivetrain if you get air. Great stuff for some desert running.

I'm just not clear if your first focus is mpg or building up an offroad truck.Good luck

 

X2. I can pretty much count on 25-26 mpg highway out of my reg cab 4x4. But thats with stock tire size 245 75 16. If I go up in tire size, I add rotational mass and my economy will go down.

Like was said above, i could go down to the 3.73 gears and probably gain an additional 2 mpg highway - a 28 mpg 4x4 pickup would be sweet. But its not worth the effort, and 0-60 performance, especially around town, would suffer.

 

just throwing my 2 cents and im out of here before the retarded stuff starts.

i have a trd off road prerunner v6 2.5 inch lift on 285-75-16 A/T i still get 19.5 mpg highway prob will average a bit better in the summer. mix driving is aroung 17.5-18. best i ever got stock and lifted stock size tires was 23 which was rare normally was 20-21 highway 17-18 mixed driving.

my experience with similarly set up 4x4 are 17-18 highway on more of a street tread. and 15-16 with the more aggressive trucks.

point of the whole thing you will loose mpg with bigger tires (not due to lift) compared with 4x4 you will still be getting better mpg. biggest part is learning how to drive your truck to get the best out of it. my dad has an f250 turbo diesel and frequently gets 19-20 mpg. when i drive his truck im lucky to squeeze 17-18 out of it. just got to feel it out.

im out good luck im sure this will be a bashing thread in no time

 

^Yup, the driver has a lot to do with it, too. If I granny mine, I get decent MPG, considering the larger and heavier tires, aggressive tread, and mild lift. However, I live 5 miles from work so I don't care.

 

I noticed when I went from 245's to 265's that my odometer reads 10 miles, in actuality I have gone 10.38 miles. I tested this with a gps when I all of a sudden was getting a little less mpg. I am also reading 76-77mph instead of 75mph.

 

Thanks every one! What im trying to do is have the most fuel efficient good looking offroad truck. Whats the regearing part of 3:4 and so on that ive never heard of it. What is is and what does it do exactly thanks?

 

Your rear axle gear can do a few things by changing it. 1) is when you change tire size your speedometer is off, and, 2) bigger tires wont be as easy to turn. If you regear you can get your speedometer accurate again, or gear higher yet for more torque. A loose example is startin a car rolling in 1st gear compared to 2nd gear on some vehicles