How in the world are you getting that type of mileage with 35s? How are you calculating your mileage? Maybe stock i could see you getting that but not with 35s. what other mods have you done?

the 35's are on my '94 which is a "2nd Gen 4runner". It has a 3.0, not a 3.4. we're talking about MPG on a 3rd gen 4runner, 3.4 Auto... that'd be my girlfriend's stock '00.

Get 12-16 if I am lucky. Between the larger tires, stock 3.90 (maybe 3.73, not sure) gears, the rack of lights and spare tire on roof, and most of all the SC with my lead foot. I try to stay out of the gas pedal a bit more now with premium fuel running over $3.20 per gallon in my neck of the woods. But, sometimes you just have to nail it to the floor for the fun of it!!


Ricochet

I guess I have a 3rd gen? It's 2002 sr-5 Last of the 3rd gen right?
I bought it with 59,000 miles stock but with optional 16" rims. My first tank registered 17mpg combined - including some 4x4. I filled it back up with 17 gallons and computed mpg.

*can I put manual hubs on this? (I'm not familiar with this type of 4x4 system) If I can, shouldn't it improve mpg since the front drive line is not turning?

I've been averaging 16-17 mpg. The worst was 10 mpg while towing a trailer. The best was somewhere around 21 mpg when it was still stock. The front bumper and lift lowered the mpg because it worsened the aerodynamics around the front tires.

lynchknot - yes, you have the last year of the 3rd gen 4Runners.

I expected some improvement in mpg when I installed manual hubs a few years ago, but it was essentially a negligible difference. Manual hubs for 3rd gens basically aren't worth the trouble for the large majority of people. They cost about $1000 if you find a decent price for the full kit, like what ORS sells. You have to replace some major pieces, including the front axles, front wheel bearings, hubs, and other parts within the spindle. I saw value in it for myself in other ways due to hard off-roading, such as if I destroy the front diff with the front locker, I can still reasonably easily get off the trail in 2L. It is nice that my CV boots last longer with the manual hubs. (Now I just break the axles before I need to change the boots).

Thanks Jeff. How large of a lift made your mpg suffer? I was thinking of a 1" body lift and larger tires myself. I was told 265/75/16 will fit as opposed to stock 265/70/16 without any body lift - but finding a tire shop willing to go the extra size is not easy for some reason. I'm already scraping stuff. I'm not so used to small tires and ground clearance. My suburban had only 32" but was plenty. These are what? 29"?

*glad to see Toyota got their last 3rd right as there seems to be no recalls. I like the new version but could not pass up a "used" price and could not justify spending $1000's more - even on a 2003.

265/75/16 are

265mm * .75 = 198mm = 7.8"

16" + 7.8" + 7.8" = 31.6" tall (ie a 32" tire)

These tires will not fit in a wheel well design for 31". Having said that, the 3rd Gen can fit these pretty easily and they are a good compromise between being a plus one size for offroad and not giving up much on the street. If you have 265/70/16 currently, you have what is considered a 31". After correcting for speedometer error, I didn't loose much mileage (maybe 1mpg) going to 32's. With 33's I seem to have lost another 1 or 2mpg.

Wow, my suburban has 32"x15 and they look huge compared to these stock tires. - so are you saying my 3rd gen wheel well is designed for 31"+?

*can the mpg be corrected by changing final gear ratio to reflect stock gearing or is it rotational mass that is affecting mileage?

I found a great online calculator that calculates actual speed if no modifications made other than tire size: http://www.net-comber.com/tirecalc.html

I started out with 1.5-2" of suspension lift. Mine is now at around 2.5" of suspension lift, still no body lift. Even after changing diff gears, the mileage still suffers from larger tires. The aggressive tread itself actually has a small effect on mpg, too. The additional rotating mass of larger tires makes it have to work harder to accelerate, so you'll use more gas that way. At highway speeds, aerodynamics are worse due to such a large area of the front view of the tires being exposed directly to the oncoming air. That's partly due to larger tires and a lot due to an off-road bumper that's designed to give more clearance at the outsides of the bumper. The stock bumper tried to go as low as would still look good to push air away from the front of the tires.

The illusion is also because one is on a 15" rim and the other on a 16". One inch is "hidden" in the rim. A stock size on the 3rd Gen is 31". With a bit of coaxing 32"s fit. With a lot, 33"s. Go nuts and 35"s somehow fit in there with lots of lift and pounding/cutting. 33"s are pretty heavy compared to the thin wall stock 31"s. That mass, wind resistance and open tread greatly affect mileage.