Big Diesel, MPG increase ideas?

[Isaac Zachary]

Originally Posted by ps2fixer

For propane, I've read a little on them, and the ideal compression ratio is somewhere around 13:1 and is about 104 octane... This all makes me want to get a cheap (and old) VW diesel to experiment with.

My old 1985 VW diesel had a CR of 23:1 IIRC. Probably not very propane-only friendly. Modern diesels have a far lower CR. But they also have a turbo charger. Of course the danger of having the turbo spool up and cause the propane to detonate can be negated by installing a pressure valve as has already been stated.

[freebeard]

I have one in the carport right now. I need to find a good home for it, preferably someone who can swap a TDI into it. That would vastly increase the driveability.

[ps2fixer]

Small update on the red truck, I found why the power didn't seem quite right. The passenger side exhaust manifold to pipe bolts are rusted out so a massive boost leak. Had a chance to do a true cold start on it to get an idea how healthy the injectors are and such and once the glow plugs got some heat into the head it fired right up.

There's an interesting thing I never knew about on these engines, there's some sort of valve for the exhaust back pressure while cold. With it activated and reving the engine ~1500rpm it closes as much as it can and you can hear the boot leak like crazy. The guy I bought it from was a bit shady and hard to work with, so I wouldn't doubt he had the engine warmed up before I got there.

Also he mentioned front u joint is bad the first time I called him, second time he said rear u joint is bad, then while I was there he said he thinks a tire is out of balance with no mention of the u joints (he seems to have bad memory). Anyway, all but like 1 u joint is shot, two are about to come apart they are so bad and the drive shaft vibrates pretty bad while driving so it's a fix right away type of thing. Looks like new u joints are about $4.50 each, and it looks to take about 5. Front axle u joints wouldn't be a bad idea too, front wheel bearing seals, etc. Oddly, the transfer case looks extra clean like it was just worked on or replaced, yet u joints are trashed.

I also looked into some videos on intercoolers and the 99+ intercooler can be made to mount into the older trucks. The intake plenum is two different sizes, the older one being smaller and there's 1/2 year model that had the same size as my truck and also had an intercooler, early 1999. Just about everything for that year is double priced so doing some research, it looks like I could swap out the intake plenums on my truck to the larger style and use the more common and cheaper 99.5+ parts. Not a cheap upgrade, looking like around $200-500. Short term I'm not going to focus on that too much, but I'll keep an eye out for an extra parts truck that's super cheap, maybe blown engine, trans, etc where it's like $500-800 for the whole truck. The 2001 is an option too since it has the parts, but I want to check what all it needs to get going again. Might be able to flip it for ~$2000 profit, or my dad might end up wanting it to actually drive. Hate to disable a machine that has potential to go down the road again within a reasonable price. I think I did pretty good on it though, $1300 for that truck and the intercooler stuff is say $300, front axle is around $800, running 7.3L seems to value around $2000, and a good transmission seems to run around $1000. Just about makes it sound more logical to part it out than get it going. No clue how well the parts actually sell though. It seems like I got quite a good deal on the red truck, the parts are easily worth the price I paid for it, one of those things where the machine as parts is worth more than the whole machine.

Also, confirmed, the red truck has a 3.55 gear ratio, open rear end. The white 2001 truck is 3.73 limited slip, and my dad's automatic 96 is 4.10 limited slip. Kind of crazy we have a set of 4x4 axles for all gear ratios these trucks came with (I think), my truck having the highest plus being the only manual (with creeper gear). Pretty happy about that.

Anyway, got some work to do on it, probably going to change all of the fluids and hopefully get to drive it some to get some base line figures.

[Piotrsko]

Fwiw the intercooler and radiator on my post 99 1/5 but not really a '00 truck is different because of the hood bump. The bump distinguishes the production break. Most of the true '00s have a catalyst, mine doesn't, even was certified LA APCD compliant via small decal under hood lip. The EGR tubes are known to need cleaning.

[Ecky]

I'm guessing a cord of dried ash is probably around or even under 2000# - green wood is closer to 3000# per cord if I remember correctly. I'm guessing you can get around 3/4 of a cord in a pickup bed without building a box.

From Google, here's a long bed with one cord in it:




Correct me if I'm way off.

But anyhow, that would put you at around 1500# in the bed. Surely 7.3L of diesel can handle moving more than 1500#?

Here's an image of me trailering home over 2000# of 16' fiber and strand board, behind my Honda Insight:

Note: don't try this at home.



Have you ever considered using a trailer? A truck is definitely the right tool for this job since you need to go off road, but you could probably move several times as much wood per trip if you brought a trailer with you. They're efficiency multipliers. Sure, fuel economy drops with a trailer, but you might see... what, maybe a 25% hit in economy, while carrying 6x as much wood? That would make each trip 4-5x as efficient.

You could even build an aero topper for the truck, so it gets much better fuel economy when not pulling the trailer, and simply use the trailer for hauling anything that doesn't fit inside the bed.

Shamelessly stolen from another thread on here:

[Piotrsko]

The 250 easily does 1 ton, the difference between my 250 and same year 350 is the spring spacers on the rear spring are taller by about 1/2 inch and maxload sticker on the door jamb. I drove a 6.9 26,000 lb max flatbed, worked pretty decent

[Isaac Zachary]

My Avalon has a 3,000lb tow limit. That's more than a pickup with the right trailer for it. But a pickup with trailer you could haul a lot more. My dad has a little 4cyl 80's 2WD Toyota pickup and a trailer he uses to get firewood. He gets huge amounts, I'm not sure how many chords. But his truck is also his only vehicle and gets decent fuel mileage he says everywhere else.

[ps2fixer]

The ash wood is roughly 3000lb per full cord. My old T100 held 2/3 full cord in the box with racks (7ft box, and it's narrower than the ford). Just a rough guess, the full size truck box with racks could probably hold 1-1.25 full cord. The GVWR on the truck is 8800lb but I'm not sure how much it actually weighs, either case the frame, springs, axle can handle a lot more. Generally Fords have good brakes so stopping ability shouldn't be the limiting factor w\o a trailer.

The last time my dad and I were getting wood, I'd haul 2 face cord (1/3 of a full cord) on my T100 and get 3 trips in a day. I mainly moved the wood while my dad cut it. The land owner and my dad also got the same amount of wood in the same time. I don't have a trailer yet, but my dad has a flat bed he built ages ago. It hauls around 5 face cord on it and is 14ft long. It wasn't built super heavy but we've had around 4 tons on it scrapping with no problems. I do plan to get a trailer, but sometimes location doesn't permit a trailer, too much off road to get the wood, or the trails are too tight.

Since I'm planning to get a skid steer, that will likely change how I get wood. I'm thinking along the lines of trailer the skid steer on site (if permitted) and cut the wood to length for the trailer and stack logs and chain down. I'd have to pretty much have a dump trailer to unload with out it though.

I haven't looked up the spec, but pretty sure the F250 should have a GCWR of 15,000+. Here's a quick forum post I found, unsure where the person got the figures from. My truck has 3.55 gearing, but I see no reason why the truck couldn't handle the 20,000 if it's just the gearing, it's saying max pulling power of the engine. Going slower is no big deal to me with that big of a load. CDL requirements kick in at 26,001 lbs btw.

3.55 gears is 16,000 and 4.10 is 20,000 for a 1997 would be willing to bet that a 1995 would be the same

Anyway, that should mean with truck + trailer weight and around 10,000lb load I should be within the actual rating of the truck still (going with the 4.10 gearing spec and going slower). That's around 3.5 full cord or about 10.5 face cord which is quite a lot. To give context, a 40ft x8ft x8.5ft tall shipping container filled to the roof is roughly 50 face cord. A standard semi trailer is 52ft long if I remember right to give context.

Back when my dad was scrapping me, he put roughly 4 ton in the back of his F250, but decided to move the cast iron (engine blocks, heads, etc) to the trailer because the frame was flexing a little. The cab to box gap was closer at the top vs the bottom. Kind of crazy, but on a 1982 Toyota pickup 2wd, he had 4 ton on it when he went to the scrap yard. I was like 5 years old at the time, but I wouldn't doubt he'd do something like that back then. My family is pretty stubborn and push the limits on things as you can probably see. I take after my mom a bit more with is like the exact opposite so I try to stay a bit more within the bounds of what the thing is designed to do, plus there's a ton more traffic now.

Personally, I'd keep driving the T100 if I didn't need to haul the skid steer (8,000-10,000 lbs). I suspect with good driving habits I can get similar mpg though with the diesel, just slightly higher fuel cost. I drove a 1986 Toyota pickup long box 2wd for a while. 5 speed stick and I think the gearing was 3.42 which is super high for a toyota (typical is 4.10) and it would pull around 30mpg empty with a carb over flowing (float too high) and the front right caliper hanging up/dragging. I put oversized cherokee rims and tires on it since the stock ones were super tiny and the tires it came with were dry rotting, so overall even higher geared. It was a truck to get me by till I got what I wanted at the time, a 4x4 Tacoma manual. The tacoma didn't pan out though, leaf spring broke free from the frame and decided to get away from the USA made truck and go back to Japanese made. My T100 is way way way more rusty, but the frame is fine. Dana was the contractor for building the Tacoma and Tundra frames, they really screwed up on them. The T100 was originally bought for a parts truck, non running, bad computer. Paid $10 for tech info access for wire diagrams and such and repinned an automatic computer I had in another parts truck and it ran great so I just drove it. Orig computer for a stick is like $300-400, automatic... $50 replacement cost. I paid $500 for the T100, and $2000 for the Tacoma (and sold for parts/repair for $1000 but sold another parts truck with it for $900 that I paid $650 for, still a loss though).

That load of hay looks tiny compared to the farmers around my area. I helped move hay for a horse farmer for a while. Here's a photo I found that looks similar to his loads, the very top row he didn't do though (unstable at normal driving speeds).

https://i.gyazo.com/17533cd948410744...f4a6c6d373.jpg

Sometimes the farmers would be nice and let him pull a hay wagon to his house to unload, lot slower traveling but a whole lot more transported at a time. I think the truck held like 58 or 60, and the hay wagons would hold 150-200.



One thing to point out, short trips and small loads works fine. However if the distances increase, then the fuel cost and time involve just driving really eats way as a cost. That's why I didn't bother with a trailer for the last place I got wood, it's only like 6 miles away. Also getting wood off people's land, sometimes the owners can be a bit weird so it's best to not cut a bunch of wood up and leave it to make a big load, it might not be there when you go to get it.

The F250 payload (actual weight of the content hauled) should be around 2 ton (4,000 lbs), the actual physical limits looks to be around 4 ton before the frame starts to flex a bit. It's pretty hard to get 4 ton in the back of a truck though, need stone, steel, or something else that's dense.

[Isaac Zachary]

My dad once overloaded a truck, can't remember if it was a Ford or a Chevy, and snapped the rear axle in half on the highway.

[Ecky]

Originally Posted by Isaac Zachary

My dad once overloaded a truck, can't remember if it was a Ford or a Chevy, and snapped the rear axle in half on the highway.

I recall my dad losing his rear axle too, though in a rather less dignified way - he was doing a burnout in his astro van.