15 MPG 2.7l reg cab 4x4 5sp?

Seems low to me. Here is what has been done to her by P.O's.

1.) No Air box. Replaced with a cone filter. The intake air temp sensor and the MAF sensor are in tact.
2.) cherry bomb glass pack after the Cat converter. O2 sensors are there still.
3.) 31" tires. I can't recall the brand. They have have some pretty deep groves and lugs to them. They are wider than stock. I only say that because they stick out past the fender.
4.) Does not appear to have any type of lift or aftermarket suspension mods. I base this on the fact that the leafs in back are frowning and I have maybe 8" from tire to fender in the front. I cannot see any blocks in the front springs and there are none in the back either.

It seems to have plenty of power. It sounds like one of those stupid ass "fast and furious" cars though. Like a blender on steroids. I want to put the factory air box and exhaust back on it. I am hoping that helps out quite a bit. PO used bailing wire to hold the glass pack in place and it transfers significant vibrations to the frame. Plus it sounds stupid.

I know obvious problem I need to fix are the filler neck is leaking just before the tank flange. but it only leaks when I am putting gas in. Even then, it's only a few drips. In the warmer months, I have gotten out after driving and spelled gas, but never seen anything "wet" around the filler neck after driving. Only after filling. Since I have a rust hole in the bed right at the gas tank, I can see the leak clearly while filling it. From half a tank, I can go about 120 miles by the time the gauge hits empty. So if's a 16 gallon tank, 120/8 gallons...

Now if I fill it all the way up, it will seeps out that leak. So I only fill it half way until I can replace that filler neck. I am leaning towards it's this leak, but really wish it was more obvious.
The plugs wires cap/rotor are all new in the summer by PO.
I have ran a bottle of injector cleaner through it.
The air filter is pulling air from inside the engine bay which is dumb I know. That is why I want to get it back to factory set up. This is mainly just a daily driver, so I am not worried about "more power" for anything.
No check engine light.
I have not stopped at a parts store to have them look for codes, though I would think if there was a code set, I'd have a CEL lit. The light does come on during the bulb test, so I know it's there.


What I am looking to to is prioritize potential "fixes" from most to least probable to go after the most likely cause based on others experience.

Thanks for any input!

 

I get 13

 

I live in a cold state so when the temp drops so does my mileage. generally get 18.5-19.2 in the summer with just my tonneau on and it drops to 15.2-16.3 in the cold months when i put my topper on. topper adds a little weight and that is one reason why fuel mileage drops but it's also the cold. i also have the cone filter k&n Setup. no lift 2.7 and mine is an xtra cab.

 

yea that's really low. I generally average 18-19. With lift, stock gears and 35's. My dad has the same problem with a check engine light. I tested it and its the EVAP system. Somewhere around the gas tank there is a leak. It doesn't leak gas, but you can deff smell gas around the back half of the truck. But when the light came on his mileage did drop. Also IV heard when you tweak with the exhaust that some mileage does suffer, for what reasons I dont know. But I would fix all the problems with it and give it another test. One other thing... I'm not entirely sure how many gear options came with our trucks but if running a bigger tire/wheel, depending on gear ratio it will deff drop your mileage like a rock.

 

My 1st gen regular cab 2.7L 5spd would average 15 around town and 20 on the highway when I had 31s on it. Now I have 33s and regeared to 4.56 and added full armor (plate bumper, winch, sliders, skids, rear bumper) I average 17 mixed

 

18-19 with 35s on stock gears is kinda hard to believe

 

^^^X2^^^

 

I have 30's on my 96 4x4 5 speed and I get 20 around town 23 on the hwy

 

Yeah mine came stock with 28s and probably got better mileage prior to me putting 31s on, but I did that back in 1998. It also had the 3.73? Gear ratio stock and was kinda a dog with 31s.

 

dude your not doing your calculations right. you cant just assume half tank mark on your gague is really a half tank. it never ever is. half tank is more like a 1/3rd of a tank.


the only way to get an accurate measurement is fill it all the way up, reset the odometer. run it, then fill it all the way up again. then divide gallons/miles and thats your MPG.

i know you cant fill it all the way up, but im willing to bet your getting WAY better mileage than your thinking.

 

Unless my calculations are incorrect thats what it came out to on a Full tank of gas and odometer set to 0. Now I had to compensate for the Speedo being off a bit, can't remember how I did that. My Truck has stock 4.30 gear ratio not 3.73. And that was mostly highway miles and doing the speed limit.

 

Yeah the whole 55mph thing doesn't work for me mostly 70-80 w/ the tach at 3k

 

That's a good point. I'll have to wait until I can fill it all the way up then to be accurate. I do know that even on a full tank to empty I get close to 240 miles. But I only did that once! Lol
Thanks for all the input.

 

2001 Reg Cab 4x4 5spd 3RZFE, no lift on Tundra Steel wheels & 265/75/16 BFG AT E's with 4.30's, tube front bumper... I average 20ish per tank, that is about 50% highway, 50% city. I usually get about 320 miles per tank.

 

You should verify you mileage counter as well, mine is off 1/10th mile with 33's and 4.56's.

 

keeping the revs at or under 2k makes a hell of a difference. I usually get 22-23 mpg combined highway and around town

 

you need to fill up the tank all the way, reset the odometer. drive. then fill it ALL the way again to know EXACTLY how much gas you have used. then divide that by the miles driven.

if you do it upon assumptions of how much fuel you have used you will ALWAYS be off.