@BLSTIC
Yea, it kind of seems most trucks are quite the nightmare for areo, kind of the nature of the beast. I almost got a 2wd Van with the same engine that was converted into a truck, the front would probably be more areo, but the back half with a flat bed and tommy gate would be terrible.
It sounds like you've had a lot of experience with areo, and everything you said makes sense to me. clearly changing the shape of the cab isn't a simple task, but top cover over the roof is an interesting idea.
The truck does have the rain cover things for the door windows, I haven't looked in person, but in the photo it looks to curve a bit where the air might stay attached and depart at a slightly better angle (in my mind atleast). I suspect doing something similar on the A pillar and matching it on the door could help round out the edge a little, probably hard to get solid gains.
I know the underbelly areo is probably the worst on it vs most other vehicles. My thought was something like a fairly heavy rubber (similar to a mud flap) that hang down from the front bumper to help push the air around the front instead of allowing it under the truck in the first place. The rubber idea was so it could hit inclines and such and bend out of the way, and the weight would keep the shape somewhat well at speed. If That idea worked out well, I suspect the side skirts could be done the same way so performance off road wouldn't be hindered, but get the benefits of better areo.
The side skirt setup I haven't seen before, pretty interesting idea, I would like to reduce road spray since road salts really kill vehicles in this area.
The truck does not have an intercooler, I know that's a huge power and efficiency upgrade for the engine, I haven't had a good luck to see if/how I could make that happen. I suspect anything, even a thin intercooler would be better than nothing.
For the fuel injectors, the truck has 190k and the injectors sound to keep a good spray pattern for a very long time, the internals get out of spec though. This is a very unique design injection system that was designed by CAT that IH bought rights to use, to be installed in a Ford, weird company politics huh? Basically the engine oil is ran through a high pressure oil pump to bump the pressure to 500-3000psi and the injector uses that to increase the fuel pressure to direct inject into the engine at up to 21,000psi. The fuel injector is also cooled with engine coolant. The design is called HEUI (Hydraulic electronic unit injection). Because of that design, these engines require a good cranking rpm to fire off, so cold weather with a weak starter or batteries is about the worst case scenario for this truck. I got it with a new starter, and it fired right up with temps just below freezing.
The 2001 truck has a bad starter, so testing out a "high torque" version of the starter on it. It's a Denso design, while the OEM design is Mitsubishi. The one I got is a china knock off, but the core design should be the same and for just over $100 it's quite cheap for being a massive starter (4kw, over 5hp!).
The fuel pump is external to the tank, so checking pressure and flow is possible. Generally people focus more on the fuel filter, and check the flow when refilling the filter housing to make sure the screens in the tanks aren't plugged. The fuel pressure these trucks run at I think is around 40psi.
I've watched a few videos about these engines and signs of bad injectors and such, and that hard diesel knock, the almost metal to metal type of sound is the sign of bad injectors. Mine sounds great, it has the diesel noise, but not the hard knock. This is probably something better to show with examples, so here's a couple youtube videos.
Fresh rebuilt engine (mine sounds extremely close to this one) -
https://youtu.be/BVKlEKbRmBQ?t=460
This one sounds to have the knock noise, kind of a tick. Almost sounds like a gas injector.
https://youtu.be/a-yo0mqThzU?t=79
From what I read, bad injectors that sound like that give less power and mpg so getting some base line numbers would help keep an eye on the fuel system, same thing for the rest of the fuel system, less fuel pressure or flow would also cause lower mpg and less power. It does seem to have a bit of a week bottom end, like taking off ~1000 rpm, but it also has a bad U-joint I was trying to baby home, and I think the exhaust side of the turbo is dirty. I clearly have some work I have to do to it before it goes on the road any more.
The down pipe is an interesting one, I'd have to check it out. I know the van's with this engine had a very restrictive down pipe, the 2001 truck I got already had it replaced, or factory it's not like the vans. I think this 95 was the same way. Could check the diameter, I suspect it's 3in and I've read people running 5in exhaust (with tuners etc) get a 4in down pipe.
For how far I drive, I don't work a "normal" job any more, so I go to town every 2-4 weeks (~50 mile round trip) , and the post office about 3 times a week (10 mile round trip), I probably put 5-8k miles per year on my vehicles. I have a car and the truck, the car is for general driving (town, post office, etc). The truck is for wood hauling, moving equipment, etc. The Toyota wasn't doing bad, but I'm eyeing some larger equipment.
I favor the older vehicles a bit more, but I was thinking of a Prius, but the Lexus brand impressed me so much (it's a high end Toyota). My 1990 barely has any rust and it's the first year they existed. Over 10 years ago my first vehicle was an Oldsmobile cutlass ceria with just under 100k miles it died due to rusting out just like the corolla (gas tank straps and the cross support it bolts to), except the corolla has 305k miles (I put 80k on it).
Money wise, I live a unique life style, 100% debt free. I recently got a couple credit cards just to build a credit score because I found out auto insurance here takes into account your credit score and a person that has zero debt (no credit cards, loans etc) has a pretty poor score so they charge extra for no logical reason. I generally gravitate to cheaper older vehicles that are known to be reliable since cost of replacement is so much cheaper. Things happen so I'd rather be financially secure in the way that I can buy another vehicle at a drop of a hat in the case of a wreck than to pay for full coverage and only have the option of cashing in if I got in a wreck and likely still pay more than the benefits offered (they have to make a profit somehow).
I have about $1000 into the Lexus, it's worth probably $1500, the corolla I paid $600 for, put probably $500 in parts into it, but with it being rusty it's probably a $800 car after the gas tank straps are fixed. The 2010 Prius seems to run around $12-20k with my quick searching for local listings. The Lexus car I'm thinking about I think was around $6-7k. I bought the V8 car just to experience it and it was $650 with a couple issues (power steering and wheel bearing).
Anyway, the Lexus gets around 20-22mpg on reg gas I got 27mpg on the trip home on the express way going 70mph, so the math would have to be against the car since the Prius can't haul a Skid Steer xD. 21mpg vs 51mpg is about 59% fuel savings for a vehicle that costs me roughly $523.81/year (5000mi/21mpg*$2.20/gal). That's $309.05 savings and 38.8 years for the break even point, or return on investment. I used a higher fuel price since the current prices are lower than they've been hanging around plus it favors buying the Prius more in the math.
I kind of did the same thing for the 2007+ Tundra option, worse mpg, less capacity, and the truck costs more, it's hard to offset the Ford's price even with some repair costs added on top. I know people say time is money, but that's not quite true, time is only money when your time is being converted to money (aka at a job, or a profitable hobby/business). I'm willing to invest some time to save the repair costs, and know the job was done right.
I'm into investments a bit too, a pretty solid figure is 5 years ROI and 5 years after that to double the initial investment. That's an average of 10% gains which is pretty common in the stock market per year. Like say a solar system to off set the electric bill, if it doesn't pay for it's self in 5 years, you'd be better off throwing the same money in the stock market, housing market, etc. Of course their life span is longer, so 10 and 10 works too, just higher risk of something having a problem in that time span (20 years total).
I find it interesting you have two similar vehicles in your sig, and the older one you pull slightly better mpg out of. I know the sig vehicles are pretty old for the fuel logs so maybe you don't have them any more. We don't really get anything sub compact here, I figured with such a small engine they'd get a bit better mpg, maybe the emission standards are strict in AU?
@oil pan 4
The video I watched on the propane injection system was a bit of the opposite, it only allowed propane once it met a min boost level, and the throttle wasn't at idle. I haven't looked into them much though so I suspect at higher load/rpm it might have special cases too.
For the turbo, it is a power stroke (one of the first years to have it), 93 maybe 94 it was a 7.3L IDI (no turbo), the 2001 truck I suspect has a slightly larger turbo, not sure if it would be worth the effort trying to see if they interchange or not. The 2001 truck has a lot of electronics going on that I'd have to check into. Intercooler I'll have to look into for space and such. The grill is fairly thick, so might be able to modify that to sneak a thin one in, I don't think it would do any good putting it behind the radiator with an electronic fan to save space.
I'm thinking with some basic mods and my driving style I should be able to hit 20mpg pretty easily. I'm not expecting too much higher since I don't plan to drive the truck often, so getting the experience will be a lot slower than like with my corolla which I was driving ~80 miles per day for work.