This is my first posting, so I thought I'd make this well worth my while and test the waters here at YotaTech.

I own a 90 4x4 3VZE 123k miles and have had it for over 3 years now. I've lifted it 4" suspension, 2" body and had 35's on it for a little while. After I realized those big meats ate gas like a fat kid eats hoe-hoes, I put the factory size tires back on. I haven't done any other mods to speak of, but my gas mileage still seems a little crappy. On the highway, I run around 3300-3500 rpm's while going 75mph and the poor thing doesn't seem to want to pull me up hills very well. It'll slow down a little and the cruise may even reset itself completely. Also, it seems that the colder the weather is, the worse the mileage gets. In the winter I was averaging 13mpg, and just recently when the temps were in the 90's I got close to 17mpg. This may seem pretty good but I remember getting over 20mpg even after I lifted the truck June02. I took it to the dealer about 2 months ago & they said everything was hunky-dorey.

Any suggestions or help in this matter would greatly be appreciated. I love this website! Reply on here or email me at fredtheturd@yahoo.com
Fred

 

[hijack... sorry]

you mentioned fuel economy... and it got me wondering, i dont even know how many gallons my car holds... its a 95 with the 3.0L and i only get about 210 miles to a full tank in the city... im guessing its about 18-20, does anyone know for sure?

 

I have about a 15-16 gallon tank and in the city I get batter gas mileage than I do on the highway with cruise control. I'm not sure if this is because I'm running lower rpm's or what.

 

I get about 220 a tank which translates to about 15mpg.

fredtheturd, it seems like you are running too many rpms at that speed. Has it ever been regeared? Also, try doing the usual tune-up stuff and your mileage will improve. Don't forget that 02 sensor.

 

be happy getting the mileage your getting... i am running stock height, 31's and 4.10 gearing and i only get 11mpg in the winter and 14mpg currently... slow on hills, all stock 3.0's are... there are a ton of threads about this do a lil search.

 

Fred, that sounds about normal to me. You have an auto tranny right? The lift makes for more wind resistance at highway speed, the aerodynamics of a brick wall.

 

You guys are going to hate me but I get 20-21 mpg on the highway with 4.56s instead of 4.88s.

 

So what's the trick? Are you running lean?

 

I don't believe it's ever been regeared. I don't see why it would have been. The truck was completely stock when I got it. No lift, no big tires, so I couldn't comprehend why anyone would regear it. I called Tim @ DOA a while back & he mentioned something with the TPS. Does anyone think this could be the culprit? Does anyone know anything about this animal? I checked the resistance at the different throttle settings & all checked out except for the closed throttle position. There was just a touch (100 ohms) too much resistance than specifications say. Any ideas?

 

Have you seen Roger's info? http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

 

Not that I know of. I've done all the tune-up stuff (plugs, wires, fuel filter, O2 sensor, rotor, cap) along with some power mods. I've got a high-flow cat and dynomax muffler. I've also cut out my airbox. My mileage will probably be a little better once I put my ISR back on. I also swapped in a set of rebuilt injectors last November. I've played with my timing but I think it's sitting back at 10 degrees BTDC but I do need to bump it back up a hair. The occasional bottle of Redline helps out too.

The O2 sensor is a big one along with the power mod.

That's it.

 

so what rpm's do most of you run at going say...70-75 mph? And what has been the most beneficial mod in relation to mileage & power?

 

At 70 by my speedo (it's off because of the bigger tires), I sit at 2800 rpms. I think 75 is about 3k on the dot. I don't drive that fast much because its going over 80 for me.

Everything adds up a little bit. So doing one or two things to help your mileage will work a little but not as much as doing all of them.

 

i am running 31x10.5 on a 94 5sp. i get about 15mpg and get usually about 250miles per tank (athough i got 280 on the last one) i have a 4.56 rear end. sitting at 75 on the odo (71 on the GPS) i am turning about 3300 RPM, bump it up to 80 on the odo (76 on GPS) and i am turning just a hair under 3400. so everything you said sounds normal to me.

 

Best highway i have ever gotten in my life with all the stuff i have on it: 300 to the tank. Ohhhh it was sweet!

 

I get 20 on the highway and about 17 mixed with 4.10s and 34s I got 20 mixed and 22 on the highway with stock tires. I've got a K&N intake headers w/full exhaust, new O2, OS valves, rebuilt and balanced injectors and a few other things. I got about 13 when I was running on only 5 cylinders.

 

I got the best MPG with 4.56's!I've tried 4.10's and 4.87's, but they were worse on fuel.I guess the 3.0's like the 4.56 gear.

 

someone asked about the total fuel capacity; on my 93 i believe it is a 17 gallon tank...

 

Well, I now live in Texas & I pulled 1400 pounds in a 5'x8' Uhaul trailer & got around 13mpg. I'm not complaining at all. I put a K&N OEM replacement air filter in & changed the brakes out. I was very pleased with how she ran! Thanks for all the posts. This place is great!