JGage

The V8 was always sort of a gas hog, but mine has gotten bad.

In the beginning I'd get about 360-380mi out of a tank, with about 1.5gal remaining. Then I threw on a size larger Revos and started getting about 330mi a tank (mind you the odo would be a bit off because of the larger size and they are more aggressive tires).

A few months ago it got really bad, I'm getting 280mi out of a tank. I filled up today, computed the MPG using a calc... 13.8mpg. I haven't been towing, I haven't been driving crazy, if anything I have slown down. Either my odo is screwed up or there is something wrong with my truck.

I had Toyota clean the fuel/induction system, its got a new timing belt, the tires are great, the air filter is good to go... Still getting poor MPG. Any ideas?

Yota Runner

you could have your wife (if your married) or someone go out on a back road with you (your rig and theres) and see how far off your odometer is off by going say 10 miles in your rig and see how many miles it is in there rig. It should give you an idea if you odometer is off. My .02 it would be a cheap way to check yourself without taking it to the stealership

JGage

Well, my usual drive is reading the same as it always has... I don't think its the odo, plus I had a buddy shoot me with a trafic laser and follow me.

Rivalred

Well, the bigger tire prob is doing it and also maybe the rolling resistance with the Revo is causing more of an issue also...

A couple questions, how many miles are on your vehicle and have you ever had the TSB done for the CAT Replacement? Your CAT's might be getting clogged, but not throwing a CEL and effecting your fuel mileage.

Might to time to change your PCV, Fuel Filter, and Spark Plugs.

JGage

90k, I had the TSB for the cat done... To be honest, I'm not really sure they actually did what they were supposed to (I know they flashed the computer, but I'm not sure they really did replace the cats) because the truck still stinks every now and then.

FWIW: What is a PCV?

Fuel Filter and Plugs was next on my "try this" list.

Fallz

I've got the 265/70/17 Revos and get pretty much am at 16.5 city/rural driving. Something must be off. And thats not even counting the add'l miles traveled because of the bigger tires. Maybe I'd hit 17 with that.

Lefty

Hmmm... Fuel filter wouldn't cause bad gas mileage. It would cause lack of power, sluggishness, and stumbling (hard starts as well). Plugs ? Possibly... But you would have had to be pretty hard on your engine to cause that kind of impact.

Some things that came across my (simple) mind while reading this thread:
- Check your tire pressure ! Summers are killer on tires - especially if they are older. I've started to check my tire pressures weekly and found them to be low more often than I like to see. 42K on them right now...
- Dirty injectors or throttle body. This is remote, since your mileage shouldn't be getting THAT bad with dirty injectors or TB. Get a bottle or two of some Seafoam and have at it !
- Dump the load of tools and/or roof rack if you aren't using it. In fact the Loadwarrior I have sucks an easy 2mpg just by having it on the truck, even if it is empty. Nowadays I try to avoid using it at all due to the sucky mpg I get. Same thing with all that rolling resistance from a bunch of tools and crap in the back of the truck that you forgot to pull out after that last camping trip (that has never happened to me ! )

Good luck with your search !

Steve

pennywize

13 with a v8 seems fine to me. i was getting 13 with my 3.0 v6 went as low as 10mpg once. our 1977 350 chevy 3/4 ton got about 9 all the time

JGage

Lefty, my truck has nothing in it save the spare. Standard roof rack (the OEM one that is useless), had Toyota do the induction/fuel clean (throttle body included). Tires are good 2 go.
Starts fine, as good as the day I bought her. Little sluggish in the lower gears in traffic. The plugs are supposed to be changed at 120k, I'll just do it at 91k and see if it helps, getting the tranny flushed. Service Dept. said they don't change fuel filters, no reason to.

FWIW: They asked what gas I was using, Shell, seems a new Tundra owner filled up at Citgo and his MPG dropped by 8mpg! Burned the tank and went to a different brand, back to normal. Gonna have them look at my PCV and MAF.

Penny, I was getting 15.5-16 on average... It took a dump for no reason.

I did find a tire with 16psi in it today... But, I had checked them when I started getting crummy MPG and they were all good... I was working up and down a nasty road the other day, I think that accounts for it, because the psi was fine 2 weeks ago.

blink

Jgage,


Something definately isnt right. Im getting about 15-16mpg with a supercharged v8, lead foot, and 115F weather.

First off, try resetting your ecu so that it reverts back to its base maps. Run it for a bit and let me know if that helps. I can think of a few other reasons why you would be getting such poor gas mileage, but that would be the first thing i suggest you do before you move on to other solutions.

JGage

Well I took it to the stealership yesterday... I was gonna change the plugs, the service writers wanted me to change the plugs, and we are discussing my poor mpg.
They ask one of the head techs and he says don't change the plugs, they don't need to be changed until 120k, and its costs too much... The look on the service writers face was great. So, I didn't change the plugs. They hooked it up to the computer and drop it around, everything reads perfect, so there isn't anything wrong with the truck.
They said they have gotten a bunch of complaints lately and think we are getting bad gas in this area (I fill up at shell).

Threw in one of those TrueFlow filters today (thanks JasonB) and well see if a new/better filter helps things... I also now have PIAA wipers, so I my truck has gained 50hp!!!

The rats at the stealership did a coolant flush and refilled it to "L" not "F" bozos... Probably didn't really do it.

Gonna fill it with 93oct and see if I get better MPG or performance.

jjrgr21

what's your tire pressure?

JGage

34psi

the_gunslinger

my nova gets 6-8...but it has power, so i'm guessing thats where the complaint comes from?