ok what's up? i get worse mileage when i drive highway and less stop and go. when i first got the runner i made a 3 hour trip and used an entire tank on ONLY highway 55-60 in 4th - 5th entire time and got the worst mileage i have ever got like 14 mpg. i rarely drive out of the city, but i used about half of this last tank on highway only and i got 16mpg i usually only drive stop and go in the city and get about 19-20, so why is it worse on the highway?

 

What size engine do you have in the truck? Do you live in the Mountains?

 

2.4L Inline 4 EFI.

No, Gladstone Oregon is not in the mountains.

No clue on why this would be happening. Crazy ECU? Leaking injectors that don't leak in the city?

 

only thing i can think is that my transmission is on it's way out, so do you think that it could be causeing the motor to run faster than it should in 4th or 5th? i don't have a tach so i am not sure, but the engine sounds fine, (although i can't usually hear it about the transmission) I live at about 500ft above sea level in the valley.

 

how fast were you running?

 

I was driveing about 45 in 4th the entire time maybe once i had to stop and accelerate up to 45 from stop.

The earlyer 3 hour trip i took it was 55 in 4th and 5th the entire trip because i had to follow a trailer infront of me.

 

take it to the shop. Maybe you're timing's off or something basic like that.

 

Clutch slipping perhaps? That would explain the engine running faster than normal and that sort of thing typically occurs in 5th and 4th gear. And mayeb the O2 sensor going out, any stored codes? In town, engine runs open loop a lot, so the O2 sensor is not used a lot. On the highway, would normally be closed loop with the ECU reading the O2 and fine tuning things.

 

I just reaplaced my o2 sensor about 4 months ago with oem. also i adjusted my timing about 3 months ago and it was right on. Do you think it could be off again? i dont' have a timing light, so i'll have to see if i can stir one up. The clutch does not really feel like it is slipping, what are some signs of clutch slipping?
No stored codes yay

 

Does autozone or something have a timing light that you can use?

 

Well, driving along in 5th gear, hit the gas a bit, see the RPMs shoot up right away but the speedometer stays the same. And if you drop down a gear and repeat, then it does not slip like that.

 

no tach... yet.

 

the old school means of checking the clutch is to get the truck up to a LARGE tree--touching--and slowly let the clutch out. if the rpm is going up, and your wheels aren't digging in, that's it.

 

if you have like the 235s they get bad gas on highway because they have to turn more, so if you have like 33s or 30s its kinda weird.

 

I don't know about you, but my 91 4runner with a V6 is at about 3k rpm or more when im at 65mph or more, and I usually shift at 3k. Maybe its just me but it seems like high rpm to be cruising in 5th gear

 

my 22re with 235s and some engine mods got 20mpg on the freeway doing 85mph turning about 3400rpms and off the freeway it got 23mpg alot better than what im driveing now but it dont bother me

 

my way of finding out the clutch was shot was to drive in 4th then put your foot all they way to the floor and if the rpms go up and your not gaining any speed then your clutch is done

 

x 3 clutch

 

I've always just put my rig in 2nd or 3rd gear while crusin and mash the brake and gas, if you kill the engine clutch is fine, if it doesn't it slippin.