MPG.
hello
I purchased a 1987 toyota itasca rv back in March wiith 54,000 that did not run. I now have 66,000 and it runs fantastic with the exception of the gas milage. All the cali pollution stuff is removed and being that I am a mechanic in training i have replaced alot.tps,ecs,cumputor,fuel pump and regulator,o2 sensir,injectors,open circuit relay,fuel filter.With or without a load,with or without overdrive(I no longer use it)messed with timing,maf,tps ,proper air in good tires with alignment.no matter what I cannot get more than 12 mpg running between 55 and 65. Bought it in arkansas,Arkansas, drove to cali than to ny and am currently headed back toward arkansas.with the hills and head wind the last couple days in pa and Virginia I am lucky to get 10.I ve read in the forums people can get 16 to 18 with these little 22re engines.any ideas from some helpful sentient being.
thank you
Jef Free

 

I've always been the first one to wave the BS flag about the whole MPG ordeal. I've had 3vze and 22res and they both get the same mileage on stock tires.

 

Can you elaborate? What is the "whole MPG ordeal"? You think people get more than they say, or less than they say? I don't quite understand what you're trying to say..

 

mostly overestimate it. too many with RVs claim 15 to 18 mpg with the 22re and a four speed. i don”t believe them. i consistently get 17 to 22 mpg in my 4runner, which has a 5 speed and weighs less, with better aerodynamics.

i always record the miles driven and gallons needed to fill the tank. the calculation is consistent. i think many who claim high mpg with an rv are estimating their mileage, rather than recording the pertinent info.

 

First, always confirm your odometer is accurate by comparing with mile markers.

 

Ahh okay, thanks for the clarification wallytoo. Very interesting.

 

I also get 17-22 on my 4Runner, 22RE which is barebones on 31-inch tires.
Yes, also try the GPS apps on smartphones.

 

[QUOTE=wallytoo;52435404]mostly overestimate it. too many with RVs claim 15 to 18 mpg with the 22re and a four speed. i don”t believe them. i consistently get 17 to 22 mpg in my 4runner, which has a 5 speed and weighs less, with better aerodynamics.

i always record the miles driven and gallons needed to fill the tank. the calculation is consistent. i think many who claim high mpg with an rv are estimating their mileage, rather than recording the m


Ilog every fill up.I have to because my potentiometer does not work.
My gut tells me she can do better.ill check the mm today which is a good consideration but I bet I am in sync.I just pulled off 81s in Virginia at the Tennessee welcome center.I ran between 65 and 70 for two hours mostly drafting rigs at a safe distance.rolling hills and straights.I engaged the od only on the downhill and shut it off prior to adding any more load.I was told by the mechanic who aligned it that running the od would tear up the tranny in a short time because the torque has to come from it or the engine.Made sense to me and have not used it with the exception of the last 2 hours.Should I use the od or not?
Should I use it onlyion flats and downhills .I am befuddled with mpg and od
thanks again

 

Are you talking about an electronically controlled o/d? i would not fear using it unless you find it lugging the engine badly.
i think your biggest impediment to improved mpg is probably aerodynamics in that rig.
You could try connecting a vacuum gauge to the engine and try to optimize highest vac reading as you drive.
Aside from that, i’d want to know what your air/fuel ratio is at cruising rpm but you need an a/f meter to see this in real time.
your goal is 14-16 for the most efficient operation. Higher than 15 is lean and it may run poorly. But the idea is to run as lean as possible without running poorly or losing power.

 

Also, make sure your timing is advanced to at least the factory spec and if you have a vac advance distributor, make sure the diaphragm is working correctly buy applying suction by mouth or other method.

if you have a carb, do timing adjustments first before carb adjustments.

 

should be efi, as the title lists “22re” rather than 22r. no vacuum on a 22re.

 

even better to check it while passing through a “measured mile”. the highway markers are ok, but not exact (still better than no reference).