Fuel Mileage???

I have 31s on my 2002 4x4 v6 manual and just got over 19mpg driving it hard.

 

clarification; am i reading this right that the speedo is off by 5 mph at 60 as in; when the speedo says 65mph you are really traveling at 60mph?
if i am that means that the speedo is reading as if 31" is actually 1" downsized from what it has ben calibrated for...that has me quite confused.


I got ya ... I was going with what you said you currently have as you stated that they have 70% tread left.
at constant speeds this would help (slightly) on flat roads for economy by effectively lowering the final drive ratio.

also on my tacoma I have two stickers on the door the one with the VIN states 225/75R15 as the size and gives info such as PSI and load and the other is another factory sticker stating 265/70R16 and pressures for this size... as far as i know the 225/75R15 size is stated on the door placard on all tacoma's regardless of what they really wore.
I looked at 4 on different dealer lot's and 3 of them had the two stickers same as mine on my way through town today.
I am fairly certain that none of these trucks actually had tires that size from the factory except for the 2wd 5 lug's.

 

heres the stickers I mean.

 

I have the similar stickers. The truck originally had 16" rims but really crappy tires. I saw on the door that the 15" rims would fit so I transferred my rims/tires over from my old 4runner before selling it off for parts. (4Runner was holier than the pope). I'm pretty sure though that the tire ssize was smaller than 265/70R16. I'll have to check that tomorrow on my way to work.

As for the speedo, with my current 31's on a GPS dashboard thing on my phone... It shows me doing 60mph when my speedo shows 65mph and it trickles downwards the slower I go the less variation. It has done this since day one of me owning it. (3 years now)

 

All Toyota's do that. It's rare for a car to come off the assembly line dead on. I think Toyota intentionally sets them up on the fast side (reading faster than actual speed).

 

@GuardDog being a 2001 w/v6 4wd you would not have had 225/75-15 tires. either the PO changed them or did something stupid like I see some people do and downsize the tires.

your stock tire size is equivalent to a 31" (31x10.5x15, or 265/70-16) as @CStoy posted (I also took pictures of my two stickers).

Also check that sticker for your final drive ratio. chances are your 4runner had 3.91 and your taco has 4.10. Look at @CStoy sticker and you can see the B03A code which 4.10

Also I didn't see (maybe it was posted?) but what pressure are you running your tires at?

Another thing to note is the time traveled to work. If you have no traffic then your truck is not really warming up and you are driving slower. Do you leave the O/D off for your trip or have it on?

The speedo is off on most vehicles due to tolerances. the "31 tire is really 30.61 but calculating decimals get messy so they round up and keep you from speeding.

Also those Duratracs are heavy, they may work OK but when I switched rims/tires I gained 30lb per wheel/tire combo, this affects mpg

 

I have a 2001 4x4 DC with 3.4 and auto trans and I average 18mpg mixed city/hwy.
I have a 3" lift with 32" tires as well as an extra 300lbs custom front bumper/winch.
Previously I was only getting 15mpg until I noticed one front brake caliper was sticking as well as one rear brake drum was overadjusted and dragging.
Check your brakes after a drive, if they are sticking the rotor or drums will be very hot (don't burn yourself)
Or you could jack the truck up and see if the wheels turn freely.

 

They can do this for warranty reasons. If the speedo has you going faster than you are, then your odo will show you've gone farther than you really have, resulting in your warranty expiring earlier than it should. I believe there have been many class action lawsuits against multiple manufacturers for this.

My v6 4x4 trd 5-speed averages in the 17's mpg. I run the original tire size, 31 x 10.5 R15. It seems to get the same mileage whether I'm in the city or on the highway. I check my mileage with every fill up and I've only seen 18 mpg a couple of times. When towing I get much much worse.

 

Take the tailgate off, replace with fabric straps (premade). Watch RPM's and quick starts/stops. Smooth acceleration and not rushing up to stop signs/stop lights can help. I have a 2001 TRD, extended cab and I get about 18MPG unless I'm pulling my boat (18' Center Console), then a get 9 or 10 MPG.

 

tailgate off wont effect anything other then weight saving myth busters proved this along time ago.. i get about 240 miles per tank on mine and i drive 15 miles one way to work in the city all the time..

 

Theres something wrong with my truck. I get wayyyyyy worse than everyone here

 

Have you cleaned your MAF sensor?

 

I get between 15-17mpg or 240-270 +/- per tank depending on how I drive. Few years ago, I was steady at 270/tank then my upstream O2 went. I didn't replace it for years. One day I got tired of the shitty gas milage that accompanied this issue (down to 210/tank if not less) so i replaced the O2 but nothing changed on my MPG. I ended up proactively replacing down stream as well as my MAF (after having cleaned the MAF with no success) and fuel filter despite not having any CELs. I also, over the course of this predicament, got BF AT KOs which have to be a factor. Now, I'm back up to 270 on the high side. I'll tell you this, the mileage only started getting better after I replaced my MAF. The two O2 sensors didn't do shit. One day I'll get around to cleaning the throttle body and new plugs but I may wait until I hit 100k on the ODO.

 

I have a good idea what the problem is actually. Previous owner welded in the upstream o2 so yeaaaa. That being said no codes and it seems to be working flawlessly. I plan on replacing soon.

 

what do you mean?

 

If your drive shaft joints are worn you'd be losing a lot of the energy on the driving side to vibrations through the joint and into the driven side.

 

would i be feeling this viberation in the shifter? steering wheel?

 

2004 2.7l 5 speed 4x4, I get 10.8l/100km no matter how I drive it. (22 u.s. Mpg)

Replaced trans fluid, front and rear diff fluid and t-case. (All synthetic 75w90)
New air filter, new spark plugs (old ones were very worn) sea foam fuel treatment, synthetic engine oil/filter

All of which didn't do a damn thing for mpg!

 

I averaged 16.5 for years in my '01 3.4L (75% city driving), then it started dropping into the 15s and 14s. Never did figure out why it dropped. Sold it last month.
I did the MAF thing, removed and scrubbed the throttle body, tried a few other things too but they didn't help at all.
MAF thread if you haven't seen it yet: https://www.tacomaworld.com/threads/maf-sensor-cleaning.26177/

 

Oh yeah, how could I forget - did the Sea Foam thing too. Didn't help a bit but sure made a spectacle smoking up the neighborhood!