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

[having fun]

LOL... I get 12 mpg all day, no matter what now. Take it back to stock and don't mod it if you want better fuel milage.

Regearing doesn't correct the speedomoter, running 315s and 4.56 I'm showing 1 mile/ actual is 1.1 .

 

[Jeffy]

The only way to keep decent gas mileage after mods is to drive it sloooow. With all the mods I've got, I can still get 18mpg+ if I baby the pedal and don't go over 65mph on flat freeways. Once I start driving it even a tiny bit more aggressive and faster, I drop down quick. I normally drive in the middle of the spectrum and I average 16mpg with 80% of that on the freeway. If I'm driving it "fun" I see about 13mpg.

 

[Johns06yota]

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!

Just rule for thumb don't trust the trip computer because it can read plus or minus several mpg. The way I test my mpg is to fill up all the way and reset my trip A on the odometer. When its time to fill up again divide that number by the number of gallons you put in and it should give a pretty accurate mpg reading. Also a tune up might help those numbers a little. Granted mine is the v6 but after spark plugs, filters, trans fluid, diff fluid, greased drive shaft, new rubber vacuum and fuel lines among other things I average 24 highway and 19 city and I don't drive like a granny. I also have a 2 inch leveling kit on mine. I'd say your biggest drawback are those 285 tires as they are much larger than the stock 265/65r17

 

[07V8]

For reference, I still get over 18mpg with E 275s, armor, and premium gas.

 

[Fern]

I average under 16mpg's with a 2" lift, 265's, and a roof rack. But, I also drive with a heavy foot.

 

[Jordanbiird]

Just rule for thumb don't trust the trip computer because it can read plus or minus several mpg. The way I test my mpg is to fill up all the way and reset my trip A on the odometer. When its time to fill up again divide that number by the number of gallons you put in and it should give a pretty accurate mpg reading. Also a tune up might help those numbers a little. Granted mine is the v6 but after spark plugs, filters, trans fluid, diff fluid, greased drive shaft, new rubber vacuum and fuel lines among other things I average 24 highway and 19 city and I don't drive like a granny. I also have a 2 inch leveling kit on mine. I'd say your biggest drawback are those 285 tires as they are much larger than the stock 265/65r17

Haha exactly! See guys, i too feel its the tires. I actually had my 3" lift kit on for about 1 year, and over that time i was 17 MPG city and about 19+ Highway. But when i got the 285's installed last week, it says im getting 12.5 Mpg, so i dont get how going from 265 to 285 can jump down 5+ Mpg lol...

But yes, i think the plan is to make sure everything is tuned up, i will also be getting my alignment asap. I have made plans to drive smarter, and i will definitely check my MPG by calculating it my self..


BUT JUST 1 QUESTION FOR ALL OF YOU!:
- So do you think i should bother Regearing/recalibrating my 4runner to adjust to my 285's so that it changes gears appropriately? Or is it literally just personal preference, not being able to see my actual MPG on the console screen? Because i have no idea how to do that, and im not sure if the general shop would be able to help me with this? Thanks!

 

[Terminator03]

Those Goodyear tires are most likely E rated, which are way heavier than regular tires, even with the larger diameter taken into account. That alone will have a huge impact on your mileage so if you don’t actually off-road it, then you should’ve gone with a similar looking tire, but with a lower rating (assuming you wanted the aggressive looking sidewall design). I’m going to be doing this soon with mine, so I’ve been researching different wheel and tire combos for a couple of months now. My dash computer shows 14.7 currently, and my calculated is slightly higher, around 15 with Toyo Open Country AT2 Tire’s in the stock 265/65 size. I’m planning to go for a similar look to what you are running, but I will likely go either 265/70, or 275/70 with a lighter rating to control some of the weight. With the offset you are running, did you have much interference/rubbing running the 285s? If so, where, and what did you modify? Sorry for the slight derail, but the wheels I’m looking at are 17 x 9, with a +10mm offset, so they would be very similar to your setup.

 

[smokey73]

If you're worried about fuel mileage, you should try the Corolla mod. I hear you can get close to 30 mpg afterwards..

 

[Bumbo]

BUT JUST 1 QUESTION FOR ALL OF YOU!:
- So do you think i should bother Regearing/recalibrating my 4runner to adjust to my 285's so that it changes gears appropriately? Or is it literally just personal preference, not being able to see my actual MPG on the console screen? Because i have no idea how to do that, and im not sure if the general shop would be able to help me with this? Thanks!

It's not really about personal preference. You can probably get away without re-gearing, but it wouldn't hurt.

Note: You gear or calibrate because your tire is taller not wider. Yours just happens to be both.

265/65-17 vs 285/70/-17 is almost 7% bigger in diameter (30.6" vs 32.7")

If you want to gear up, I would consider 4.56 gears for a 33" tire, which is the route I am going.

As to the speedometer calibration... totally up to you. I didn't re-calibrate mine, but I bought a separate device with a display that has the correct speed displayed.

 

[Jordanbiird]

Those Goodyear tires are most likely E rated, which are way heavier than regular tires, even with the larger diameter taken into account. That alone will have a huge impact on your mileage so if you don’t actually off-road it, then you should’ve gone with a similar looking tire, but with a lower rating (assuming you wanted the aggressive looking sidewall design). I’m going to be doing this soon with mine, so I’ve been researching different wheel and tire combos for a couple of months now. My dash computer shows 14.7 currently, and my calculated is slightly higher, around 15 with Toyo Open Country AT2 Tire’s in the stock 265/65 size. I’m planning to go for a similar look to what you are running, but I will likely go either 265/70, or 275/70 with a lighter rating to control some of the weight. With the offset you are running, did you have much interference/rubbing running the 285s? If so, where, and what did you modify? Sorry for the slight derail, but the wheels I’m looking at are 17 x 9, with a +10mm offset, so they would be very similar to your setup.

The only thing i had to do was move the front wheel liner about 1" forward. I did 2" just to be safe. I also used a razor blade to trim the front inner fender, but i only trimmed a little bit. I did it very good, that you cant even tell it was trimmed at all. But beware, some 285's vary slightly in size and they could potentialy rub in other areas. Such as a body chop could be needed.

 

[Jordanbiird]

It's not really about personal preference. You can probably get away without re-gearing, but it wouldn't hurt.

Note: You gear or calibrate because your tire is taller not wider. Yours just happens to be both.

265/65-17 vs 285/70/-17 is almost 7% bigger in diameter (30.6" vs 32.7")

If you want to gear up, I would consider 4.56 gears for a 33" tire, which is the route I am going.

As to the speedometer calibration... totally up to you. I didn't re-calibrate mine, but I bought a separate device with a display that has the correct speed displayed.

So if i want to regear for a 33" tire, if i go to an auto-shop, what should i ask them to do? Thanks.

 

[Bumbo]

So if i want to regear for a 33" tire, if i go to an auto-shop, what should i ask them to do? Thanks.

You basically tell then you want some differential work done, and when they ask what type of work, you say a re-gear.

The gears we are referring to has to do with the differential housing. If your auto shop can’t do it, you want to go to a shop that specializes in differentials and drive line work.

If you have a 2WD, you only have to worry about the rear. If you have a 4WD, you need to do both front and rear.

Plenty of threads and pictures on the topic if you google it.
https://www.roundforge.com/articles/410-456-488-529-what-gears-should-you-get-your-toyota/

 

[jrm]

Since no ones mentioned it...

you should NOT be running the tire psi listed in the door jam and instead run those listed on your tires.

In my case that means running 40F and 42R instead of 32 all round. YMMV but this made a pretty good difference in my MPG from like 19 to 21/22 hwy @ 65-70 MPH tops.

 

[ZiaMan]

Bro...literally the 3rd google result for tire calculator:
https://www.tacomaworld.com/tirecalc?tires=265-70r17-285-70r17

 

[2003-4x4runner]

Like most people said, its normal. I went from stock to a 3" lift and 255/75-17 tires and my gas mileage dropped from 20 mpg to 17 mpg.

 

[Terminator03]

The only thing i had to do was move the front wheel liner about 1" forward. I did 2" just to be safe. I also used a razor blade to trim the front inner fender, but i only trimmed a little bit. I did it very good, that you cant even tell it was trimmed at all. But beware, some 285's vary slightly in size and they could potentialy rub in other areas. Such as a body chop could be needed.

Thanks! Trying to visualize where you needed to trim with the razor, but when you say “front inner fender”, do you mean the part you moved forward, or the actual lip of the fender itself? I’m assuming the later, but figured I’d ask anyway just to be sure.

 

[Jordanbiird]

Thanks! Trying to visualize where you needed to trim with the razor, but when you say “front inner fender”, do you mean the part you moved forward, or the actual lip of the fender itself? I’m assuming the later, but figured I’d ask anyway just to be sure.

Hey! So I moved the plastic inner liner, just the front part, which first you have to take out some screws on the bottom and then I moved it forward about 2 inches. Now the part I cut with a razor blade was the actual part of the bumper. But just the area inside the wheels well area. Like if you were looking at my 4runner you wouldn’t be able to tel it was trimmed unless you peaked your head in the wheel well. Here is a picture of how it looks:
See the edge right next to the small hole which used to screw in the wheel liner plastic? That’s where I cut a strait line.

BUILD THREAD:
http://www.toyota-4runner.org/4th-gen-t4rs/231791-jordanbiird-build-thread.html

 

[Terminator03]

Hey! So I moved the plastic inner liner, just the front part, which first you have to take out some screws on the bottom and then I moved it forward about 2 inches. Now the part I cut with a razor blade was the actual part of the bumper. But just the area inside the wheels well area. Like if you were looking at my 4runner you wouldn’t be able to tel it was trimmed unless you peaked your head in the wheel well. Here is a picture of how it looks:
See the edge right next to the small hole which used to screw in the wheel liner plastic? That’s where I cut a strait line.

BUILD THREAD:
http://www.toyota-4runner.org/4th-gen-t4rs/231791-jordanbiird-build-thread.html

Awesome! Thanks so much for the pic. Now it makes perfect sense!