why is it so low? a question i have been working on for some time. so far, the shop found there were no software updates on the ECM, the wrong spark plugs, and fouled injectors. fixing this, tuneup, oil change, some trans work, etc., resulted in an increase up to the aforementioned mileage.

re your "08 XL rab/6.5'" - what engine/trans/axle ratio are you running?

so far, it's one vote for 4.1, and one against. appears unanimous against the 3.73. ultimately, what i'm trying to do is get farther up the torque curve for a given RPM. that's why i'm asking for opinions of those who have gone before.

 

boy,you guys don't miss much, do you? yes, that is slightly smaller than stock. it's a long story, but the bottom line is that i had them available, almost new, when the cactus ate 3 of the old tires.
as to them being small for a survival truck, the difference is simply not enough to matter. remember, i'm going around, not through, and i've lost, with these tires, maybe half an inch of ground clearance. but, i've gained some resistance to punctures.
as i mentioned, when they do get replaced, i will upsize, and by that time i'll have made the suspension decisions, such as long travel vs payload, etc., so i'll know how big i can go.

i have no budget, but i do finally have a better job, so i've got more money coming in. i'm being thrifty, but not cheap, so that stretches out the time line.

 

Sharper than an adder's fang is the tongue of a sarcastic off-roader!

 

4.10's will increase your RPM's by only 300.
4.30's= 410 rpm increase
4.56's=550 rpm increase

if you are changing rear ends, i would get a locker put in too! either a detroit trutrac or a detroit locker.

 

I am considering the locker, especially if i get one cheap. i do like the detroit product.

as to the RPM's, I already knew that. the problem is that i have no idea where on the torque curve that puts me. that's why i'm asking for other's real world experience.
or, the torque curve if someone has it...

 

most trucks make their most usable power around 2K. so if you are going down the interstate, shoot for that rpm.

what driving do you do mostly?

 

i found a dyno chart. but it doesnt start till 3k rpms

 

Building a "survival" truck and using things just because you find them cheap seem to kind of contradict in my book. But any progress pictures lately?

 

Its an 08 F150 2wd with 4.2 V6 and 5-speed standard transmission and 3.73 gears with limited slip.

Swapping from 3.55s to 3.73s generally isn't cost effective, and if you jump up to 4.10s, I'd recommend running at least a 31" tire, preferably a 33. Though all of those changes are going to impact fuel mileage.

How much highway time do you see?

 

no new pix yet.
regarding costs, I don't see the contradiction you see. First of all, you're putting words in my mouth - I don't believe I said the choice is made solely - "...just because..." - on cost.
Cost is a real world constraint. if you know of a way to disregard cost in any process, please clue me in.
heck, run for president. you got my vote!

 

i would love to get that mileage with what i have.... the only difference is our rear end ratio, and you would think I would get better mileage than you do! your story convinces me there is something wrong with my drive train.

I do not agree with the idea of changing tires just because I'm changing gear ratios. I am no expert, but it seems to me you're taking with one hand and giving with the other. If 4.10 is the "correct" ratio, then why would i want to drive the effective ratio higher by going to taller tires?

the highway time is part of the daily commute. there's no real advantage, i don't think, to optimizing for the highway. I'm either commuting, or driving around the hill country property.

 

thank you, thank you, thank you!!!!

you are officially the hero of the day!!!

 

wow
check this out
http://www.youtube.com/watch?v=fYzP7idQFyY

 

DenoFL,
Where is the wow in it ? If that was your reaction to finding out it was only 2wd then yes I agree, WOW.

But it can be yours on the RBP site for the low price of $95k