new to forum looking forward to some MPG's

[gone9]

Well,
Im new here, been lurking for almost a year on-off now. I have been following a lot of Big Daves stuff with his 2000 f350 The Red Baron.

I have a 1999 f250 supercab, short bed 4dr 7.3l diesel with the following:

when I was bone stock 65-67mph I got 19.4 mpg best highway and about 14-16 town average. After level kit and tires about 17.6 best highway and town is roughly 14-15.5ish... I manually calculate since even with a corrected speedo its off a bit. I have an edge insight monitor but it seems useless for average or instant mpg.

2.5in level kit, 285/75r16 tires, AIS Motorcraft severe duty intake, straight pipe exhaust, hydra chip.

I know its not your average eco modder set up but im new and already realized the level kit and tires cost me about 1.5 on average. I take a couple trips to my home in northern Idaho to see family, hunt, etc...


Probably going to get a soft tonneau cover and POSSIBLY fab a air dam like Big Dave did since I don't have snow to deal with in CA.

Hoping to pick up a few tricks.


p.s. I may look at gearing too. I have 3:73's but I may try for some 3:55's seems highest I can fine for a superduty 7.3l. I may also go back to stock suspension and lower the rear about 1.5-2inches to level too.

I also have what diesel runners call the 08+ upgrade mirrors. A larger square mirror. it helps immensely when towing but Im gonna see about folding them and adding a small mirror on the folded section seems some see a very small gain from reducing drag with mirrors. once I have enough post. I'll show pics. they are big ones lol

[gone9]

Seemed Big dave gained 1-1.5mpg with a tonneau and I drive to sac for night school so tis about a 105mile round trip once a week plus about a 24 mile trip to work during the day.

any thougts for this tonneau cover?

soft, with sectional supports, and soft may help with drag better than a solid top plus lets me use the bed for lumber, and 5th wheel when need be etc.

cant post links yet. sorry


I really want an aercap,aeroshell or whatever the term is but seems a bit past my tools ability right now plus my wife might have a few things to say lol....

[gone9]

found another diesel hypermile dude in san fran. Not sure hes around anymore but I like his semi aerocap it appears to be about 10 or so inches below the the roof line so you can still see out the back window etc.

He even went as far as removing power steering, AC, and adding a solar kit to keep dash lights lit after completing LED switch.

[gone9]

The link below shows the diy half aeroshell.

Seemed to work well anyone else use something similar?

https://www.google.com/amp/www.instr...famp_page=true

[Daschicken]

Originally Posted by justinooo9

I know its not your average eco modder set up but im new and already realized the level kit and tires cost me about 1.5 on average. I take a couple trips to my home in northern Idaho to see family, hunt, etc...

Oh don't worry about that, we've got plenty of truckers on here. I am an advocate of getting the vehicle you want, then driving and modding it efficiently.

Lost mpg from a level kit? I'm guessing was at the same time as the new tires. Does the level kit raise the front to the same height as rear, or does it drop the rear to front level?

[gone9]

Originally Posted by Daschicken

Oh don't worry about that, we've got plenty of truckers on here. I am an advocate of getting the vehicle you want, then driving and modding it efficiently.

Lost mpg from a level kit? I'm guessing was at the same time as the new tires. Does the level kit raise the front to the same height as rear, or does it drop the rear to front level?

Just a front level kit. My truck came with the tow package so the rear end was almost 3.5 taller than the worn out springs in the front.

I’m thinking going back to stock height in front and switching blocks in the rear to still sit level. The tires were a 265/75r16 stock and I went to 285/75r16.

Budget is little low since I got a new turbo compressor wheel. 5+ more psi boost, lower egts, better low and top end, no ecm programming needed either.

At the very least a tonneau cover. But I’d love to break 20mpg or more on a 7700lb 4c4 diesel haha.

[Daox]

Welcome to the site Justin. Sounds like you have a good handle on what needs to be done.

For testing a tonneau, you can just slap a piece of wood on the back to see what it'll gain you.

[elhigh]

Getting your front back down to stock height and lowering the rear to match is the way to go. Then add the air dam, it should make a noticeable improvement. Trucks are wide open for aero improvements.

Seconded for throwing a sheet of plywood on the bed for quickie tonneau tests, and I recommend a rigid tonneau instead of a soft one, if that's the route you go. I think any flapping the top does is going to induce turbulence. Turbulence Is Bad.

This is someone's Master's Degree thesis digging into the various things you can add to a pickup to reduce its aero drag: http://csus-dspace.calstate.edu/bits...d-finished.pdf By his experiments the tonneau was only good for about 1.5% improvement, but that was with a generic "truck" shape. Your real world results, as they say, may vary.

Other trucks, especially ones modded for top speed runs at Bonneville, have run with half-tonneaus covering the bed from about the midline of the rear wheels back, with a solid bulkhead at the front. This leaves a large open space between the bulkhead and the rear of the cab. I have no idea whether and/or how big an improvement that would provide, but it's interesting to think about. If nothing else it would allow you to continue to use the truck as a truck for things that aren't too big or heavy, just toss them in over the side.

I say for the price of a sheet of plywood and a few minutes with some ratchet straps, a stop watch and a few runs down a hill, what more is there to lose? The improvements could be significant.

[gone9]

thanks for the info, looks like I have some reading (probably skimming) hahaha. I saw the little chart showing a wing from the top/rear of the cab and a cover from the middle of the bed to the tail gate but looked like more work than I was willing to do. Esp to make it somewhat nice/sturdy.

I plan on getting a couple of sheets not this weekend, but next. I already have 4 holes in my bed rails from a previous camper shell so should be a little easier.

The link I shared also shows someone making an angled tonneau cover with a two elongated trianble pieces of plywood on the side and a tonneau cover over the top. He said the angle alone was almost a 2mpg improvement but I'll start doing some more testing soon.

Truck got hit at an intersection so shes getting a facelift right now.

was there talk about how far the air dam should be off the ground? I'll probably try to make mine no higher then the lowest point of my wifes car as a reference and for approach in/out of parking lots, but did anyone see results with a super short vs med, vs super low handing dam?


oops sorry didn't see the air dam section of the calstate doc lol.

[gone9]

Im doing a nice 2000 mile round trip this December to Northern Idaho too. Im gonna bring back some conveyor belt from my Dads place. Im gonna copy Big Dave no lies lol.... I'll do some measuring but i'll probably make it as low to the ground as possible since 99% of the time I don't deal with snow