I went from 17-19.5 MPG to 12-14 MPG. PLEASE HELP! Please give me advice !!!

[Jordanbiird]

Hey guys! Here is a question i really need your help on, concerning my 2008 V8 Sport Edition 4runner.



Stock:

V8 Engine

No Lift kit

265/65/17 Firestone Destination tires

17" stock toyota rims +25 offset?



After:

V8 Engine

3" Front Spacer

1.5" Rear Spacer

285/70/17 Goodyear Wrangler Duratracs

17" Aftermarket tires +12 offset



So....

Basically, right now i am freaking out because my MPG tracker below the center console is reading 12.7 MPG.



I just got the wheels balanced and installed last week, and so far i have only driven like 30 miles around the city.



Before:



Highway - 18.5-19.5 MPG

City - 17.5 MPG



Now:



Highway/City 12-14.5 MPG? Im still not sure since i havent driven too much yet.





But anyways, i need help determining if my MPG is actually that low, or if there are several factors playing into this problem. So far, i have came up with a list of things that could influence decreased MPG in my 4runner.



1. Going from 265 to 285 tires

2. Speedometer needs recalibrated

3. Needs alignment (No i did not get an alignment yet)

4. I have a 3" lift kit installed







Do you guys think my MPG is really that bad because of getting new tires? i thought it would change like 1-2mpg or so, but not that much! I cant afford to get below 15 MPG, so im hoping i can achieve higher than 15 by fixing some things.



So do you guys think its the tires, or could it be any of the other things i listed, or do you guys have any other ideas?



What do you suggest i do? If i need to get the speedometer recalibrated, is it worth it to do it myself, or take it to a shop?



PLEASE RESPOND IF YOU CAN, thank you so much!

 

[Flash Runner]

Can’t say for sure, but I’m not surprised bc my V8 came with a lift (OME, so I didn’t know the mpg before) I never get 16 MPG (even all highway), I avg 11mpg but I do mostly city. So I wouldn’t be surprised if it’s all bc of the 3” lift

Interested to see what others say

 

[LarsBars]

Your new tires are considerably larger than your old ones. The vehicle does not compensate for that so your actual mpg should be better than what the computer says. However, the lift, considerably heavier tires (20lbs per tire in unsprung weight is a lot), and not regearing are all going to take a toll on your fuel economy.

Figure out your real mpg dude! Fill up your truck and go for a drive (the farther the more accurate) then fill up your tank again. Use a mileage app on your phone to figure out how far you actually drove and divide it by how much gas you used to give you an accurate mpg figure. You can also compare your recorded mpg to your trip computer so you have a better idea of your mileage in the future. For example I know my actual distance is 6% more than what my computer shows.

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[Seymore Butts]

Make sure to use the same gas pump at the end of your mileage test as you used to fill up at the start of the test.

 

[OppoTaco]

I use a phone app to track my MPG. As other members have said, just input your miles at your fuel fill ups.

If you want to verify the accuracy of your speedometer and odometer with the new tires, download a speedometer app for your phone. It uses GPS to report distance traveled and current speed.

Both apps are super easy to use, very handy and free.

 

[Morphyne]

I feel bad for you if you thought you could afford a lift, new rims, oversized tires and not bad gas mileage.

Aside from that its basic physics. You are spending more fuel to turn more weight. That being said. You have other math to contend with as well. Your computer doesn't know you have bigger tires.so its giving you false readings.

Bottom line. You are getting worse gas mileage. That's the cost of what you've done to you vehicle. However. It's not as bad as your computer makes it out to be.

 

[Bossman]

http://www.toyota-4runner.org/4th-gen-t4rs/43439-mpg-drop-lift-tires.html

http://www.toyota-4runner.org/4th-gen-t4rs/235390-lift-tires-wheels-=-terrible-mpgs.html

http://www.toyota-4runner.org/4th-gen-t4rs/226357-low-mpg-out-ideas.html

http://www.toyota-4runner.org/4th-gen-t4rs/149710-11-2-mpg-avg-after-lift-ride-height-question.html

http://www.toyota-4runner.org/4th-gen-t4rs/204598-mpg-affected-much-tires.html

http://www.toyota-4runner.org/4th-gen-t4rs/210711-gas-mileage-improved-lift.html

 

[NinjaOne]

Those MPGs are fairly average. I'm more surprised that you were getting 17mpg before. My computer is right at 13 mpg last I checked.

Oh, and that computer isn't super accurate and as others have said isn't corrected for the change in tire size (speedo is also off )

 

[BackOff]

Did you disconnect the battery?
If you did, Drive more, 30 miles is no enough for the computer to read right.

Also check for a bad brake caliper dragging, that could reduce MPG.

Clean you air filter and MAF.


Don't drive like a hooligan...that will help you MPG, drive like a old fart.

 

[wkeryder4]

Sounds perfectly normal. It honestly shouldn't be that much of a surprise, taller lift, considerably heavier tires and wheels etc. You're going to see a substantial drop in mpg. I average around 12-14 even working the calculations out by hand and driving like a grandma. Don't know how people claim they are doing anything above 15mpg with a lift and 33's. Its just something you need to expect when you choose to modify your vehicle, especially with older motors that aren't built for efficient mpg numbers.

My best advice for improving your mpg would be to take everything off and go back to stock. Lifted 4x4 suv's is not the best vehicle choice if you're worried about gas mileage.

 

[Jordanbiird]

Sounds perfectly normal. It honestly shouldn't be that much of a surprise, taller lift, considerably heavier tires and wheels etc. You're going to see a substantial drop in mpg. I average around 12-14 even working the calculations out by hand and driving like a grandma. Don't know how people claim they are doing anything above 15mpg with a lift and 33's. Its just something you need to expect when you choose to modify your vehicle, especially with older motors that aren't built for efficient mpg numbers.

My best advice for improving your mpg would be to take everything off and go back to stock. Lifted 4x4 suv's is not the best vehicle choice if you're worried about gas mileage.

Yeah i dont understand how people get good MPG, i just watched a video of a guy who averaged 18.7 in his Tacoma, and when he went up to 33" tires and a lift kit, he only went down to 18 MPG average...

 

[Bumbo]

For the most part it sounds normal to me too...

For most accurate results, calculate actual MPG by filling up at the same pump, and dividing the gallons filled by the mileage recorded before and after fill-up.

Larger tire = more weight = more gas
Wider tire = more rolling resistance = more gas
Lift = less aero = more drag = more gas

If you wanted better MPG with a lift, you should have looked into something a little more conservative in lift height, maintaining a little forward rake, and picking a solid road tire like a Michelin in a close to factory size.

For a "big tire / tall tire" I would have gone with a 255 instead of a 285. That's generally my "compromise" which also happens to work better on many levels (weight, rolling resistance, and more PSI on contact patch).

Speedometer calibration I do via scan gauge, I think error is a small % in the ballpark of 2-4%

I think driving style has a lot to do with it too... its not hard for me to get into the single digits when I am being very aggressive in my driving.

You should align your truck sooner than later.

 

[wkeryder4]

Yeah i dont understand how people get good MPG, i just watched a video of a guy who averaged 18.7 in his Tacoma, and when he went up to 33" tires and a lift kit, he only went down to 18 MPG average...

I've seen some people go through some crazy mental gymnastics to prove to themselves that they are still getting excellent gas mileage. ie. calculating percentage in tire diameter increase compared to stock, wind factors, speedometer offsetting, odometer not being correct due to a larger circumference tire and mph not reading properly, elevation changes, tank actually holds 23gal not 20 and it just gets even more ridiculous.

This is not a wise hobby for someone that is concerned about their gas mileage. I've never gotten more than 270 miles out of 20gal of fuel since I lifted my truck and went to 285's and I have no problem with that whatsoever. I'm not going to start carrying around a ti85 calculator to justify the modifications I made to my truck.

 

[Jordanbiird]

I feel bad for you if you thought you could afford a lift, new rims, oversized tires and not bad gas mileage.

Aside from that its basic physics. You are spending more fuel to turn more weight. That being said. You have other math to contend with as well. Your computer doesn't know you have bigger tires.so its giving you false readings.

Bottom line. You are getting worse gas mileage. That's the cost of what you've done to you vehicle. However. It's not as bad as your computer makes it out to be.

People tell me not to worry about Recalibrating because its just preference if your actually going the speed it says you are, but other people have told me not recalibrating creates problems like, your vehicle will be switching gears at different MPH and it can be bad for your vehicle... is this true? Or should i not worry about recalibrating it at all?

Thanks!

 

[ran]

when I was all stock the first 20,000 miles I got 22 MPG on the Interstate. miss those days.
_________________
2007 SE V6 Titanium

 

[Bumbo]

People tell me not to worry about Recalibrating because its just preference if your actually going the speed it says you are, but other people have told me not recalibrating creates problems like, your vehicle will be switching gears at different MPH and it can be bad for your vehicle... is this true? Or should i not worry about recalibrating it at all?

Thanks!

The right way to recalibrate is to re-gear the truck to something like a 4.33, 4.56, 4.88 or whatever is correct for your new tire diameter… If you just want a speedometer correction, just get a Scan Gauge with a corrected read-out or something similar and leave the truck alone.

Keep in mind that a re-gear actually corrects a lot more than just what it reads on the gauge. Too large a tire diameter and the truck starts to feel like it’s always in the wrong gear or that ur always lugging the engine.

Edit: After thinking about it, maybe a re-gear does not actually fix the readout on the speedometer? Considering the car still doesn’t know the final diameter of the wheel the error might still be present.

 

[Bumbo]

I've seen some people go through some crazy mental gymnastics to prove to themselves that they are still getting excellent gas mileage. ie. calculating percentage in tire diameter increase compared to stock, wind factors, speedometer offsetting, odometer not being correct due to a larger circumference tire and mph not reading properly, elevation changes, tank actually holds 23gal not 20 and it just gets even more ridiculous.

This is not a wise hobby for someone that is concerned about their gas mileage. I've never gotten more than 270 miles out of 20gal of fuel since I lifted my truck and went to 285's and I have no problem with that whatsoever. I'm not going to start carrying around a ti85 calculator to justify the modifications I made to my truck.

Those math gymnastics are pretty weird approach when one can simply divide the actual mileage traveled by the actual fuel consumed. I don’t see how it can get any simpler for actual real world consumption figures as it already takes all that into account.

Bottom line is you get what you get… if you are lifting and getting bigger tires for looks on a daily driver or use this truck as a commuter, you are paying a lot more for a lot less in the name of vanity. If you actually off-road, you probably don’t really care what ur gas mileage is because it’s just part of the setup and the cost of doing business.

 

[cloud]

I had the exact same issue, I don't care to read all of these detailed responses so I know some or all of this is repeated.

Check your gas cap, mine had zero resistance so I got a new one.

Clean your MAF and throttle body.

Clean your injectors.

I did all this and my truck jumped up to closer to the numbers I had before the OME lift I installed. I have the same tires as before the lift though, I also added an ARB bumper and rock sliders, and window tint.

Maybe flush the radiator and diff fluids, hell do the twelve quart tranny flush using the intercooler hose trick. I did all of this within the last thirty days, except the lift and bumper, so I can't say what had the most or any impact. I really think my problem was the gas cap, and the fact that I had been driving in three wheel drive for a while.

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[Inv4drZm]

This last trip to Moab I got almost 16mpg on flat ground with my 35's and full armor, no OEM roof rack, V8, 3" lift+1.5" body lift. Calculated by hand and adjusted for the 12% the odo is off. Took it easy going 75mph or slower most of the way which is the key.

My brother has a V6 FJ with the same mods, 34's, but a fully loaded roof rack. (Not good aerodynamics at all) and always filled up with more gas during the same exact trip.

 

[Atlanta_man]

Completely stock, with Michelin LT tires, I get 15 actual mpg around town. Hardly varies at all.