Big Diesel, MPG increase ideas?

[Isaac Zachary]

Originally Posted by BLSTIC

I can't believe I'm saying this (because it's EcoModder.com not TightwadDriver.com), but how much spare cash have you got and how much load-free driving do you do?

A 2010 Prius gets 51mpg according to the EPA. If you sell the Lexus and the Corolla you shouldn't be too far off buying one.

Your F250 probably gets 17mpg, or 5.88 g/100mi, at $2.44/gal that's $14.35/100mi
A Prius gets 51mpg, or 1.96g/100mi, at $2.05 for regular that's $4.02/100mi

At $10/100mi price difference that's 50,000 miles in total to pay for the entire cost of a 2010 Prius, and that's only considering fuel costs. The rest of the operating costs are so much smaller too

Good point. A lot of people these days think they need an AWD/FWD pickup or SUV because that's what the media tells us. I'm not saying the OP doesn't need one to go get his fire wood and driving in snow. But even for those things a sedan, hatchback or station wagon might me all that's needed.

What I did personally is I got a used 2013 Toyota Avalon HV and all I've done to it is install a block heater and a tow hitch plus I picked up a set of wheels off a burnt car for cheap and threw studded snow tires on it. Now I have a roomy car, much roomier than any SUV or Pickup I've ever been in both in front and rear seats, that gets 40mpg, can haul up to 1,000lbs on the trailer, which is also exactly 4" x 8" so any sort of panels, like drywall, plywood, foam insulation and the like, all fits perfectly, and it drives perfectly well here in the steep, icy Colorado mountains. Great for camping, fishing, skiing, and lots of other off road/winter sports as well as all the construction and remodeling I've been up to lately. Leather heated seats, dual climate heater, sun roof, multi position electric seats, and a one of the biggest trunks on the market (and a really happy wife as a result). Plus it has one of the lowest statistics for death to passengers out there. Our first year we did over 30,000 miles in it.

[ps2fixer]

@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.

[freebeard]

Twenty posts in <24hrs!

As a first approximation, I'd go for 1/3 hypermiling, 1/3 powertrain and 1/3 aerodynamics.

For the aero, fix the hood and dump the bug deflector. The airdam is fine, but add air curtains on each side. Your search term is 'edgarwit'. Seal the cab bed gap. Maybe a slab of magnetic stick-on car door sign material.

A compound-curve aerocap is best, but a half-tonneau is very close. You'd have the front half of the bed open and a trunk/toolbox/camp kitchen with a vertical tailgate.

For the hybrid drivetrain, consider that 20hp GM E-assist altermotor. It would need a controller and 55-72v battery pack, but that how you get serious regen.

[cRiPpLe_rOoStEr]

Diesel engines tend to respond quite well to supplemental water injection, and eventually worth to consider a simultaneous usage with propane, to mitigate its tendency to knock. On a sidenote, last Saturday I saw a Mercedes-Benz truck fitted with supplemental CNG injection, which is becoming more widespread in my country (Brazil) recently, and since it has better anti-knock properties than ethanol it suits well to the lean-burn in a Diesel engine. And even though some CNG fumigation might decrease the Oxygen concentration at the combustion chambers much like an EGR does, it's better than EGR as the CNG increases the flame spread for a more accurate burn of the Diesel fuel, not only generating fewer soot but also extracting a higher amount of energy from a given volume of Diesel fuel or even if it's partially replaced by the CNG to retain stock power and torque figures.

[Isaac Zachary]

Originally Posted by cRiPpLe_rOoStEr

Diesel engines tend to respond quite well to supplemental water injection, and eventually worth to consider a simultaneous usage with propane, to mitigate its tendency to knock. On a sidenote, last Saturday I saw a Mercedes-Benz truck fitted with supplemental CNG injection, which is becoming more widespread in my country (Brazil) recently, and since it has better anti-knock properties than ethanol it suits well to the lean-burn in a Diesel engine. And even though some CNG fumigation might decrease the Oxygen concentration at the combustion chambers much like an EGR does, it's better than EGR as the CNG increases the flame spread for a more accurate burn of the Diesel fuel, not only generating fewer soot but also extracting a higher amount of energy from a given volume of Diesel fuel or even if it's partially replaced by the CNG to retain stock power and torque figures.

When I had my diesel I was favoring doing a CNG system instead of an LP system simply for those reasons.

I like the idea of both water and LP or CNG.

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

I like the idea of both water and LP or CNG.

LPG is not allowed as a road-going motor fuel in my country, even though some industrial and material-handling applications such as forklift trucks resort to it. On a sidenote, since water injection usually requires some alcohol (most often methanol) added into a proportion more frequently around 50% to prevent its freezing, and the fact that ethanol concentrations below 80% won't self-ignite so easily, experiencing with different alcohol concentrations sound quite tempting.

[ps2fixer]

I probably should clear up that I'm not bashing buying a more efficient vehicle, generally older stuff does need more work/repairs, and if someone drove a lot more miles it probably makes a ton of sense to buy something newer.

Here's a fun photo of my dad's truck, that was a 1989 Mazda 2.6L manual 4x4 and on a good day it would get 20mpg with my dad driving it (not quite an ecomodder level driver for mpg, but not as bad as the average driver). The same racks went on my dad's T100 when I convinced him to upgrade trucks, same or better mpg, more power, bigger truck.

He burns about 20 facecord per year, I burn around 12-15. Generally we are getting ash wood, so 1 full cord (3 face cord) weighs about 2880 lb dry or 4184 lb wet according to google. The T100 hauls around 2 face cord in the box with racks and about 5 on my dad's trailer if we completely max out the load, we are looking at about 10 tons in just wood. That's clearly beyond the designed capacity of the T100 and we drive effectively empty roads slowly if/when we get that big of a load. The Ford would handle the load much better and probably get better mpg while hauling due to the nature of diesels.




Here's my car, the areo on it I think isn't super bad for the overall shape. The rear window clearly slops too fast, I can see the line where snow and such doesn't blow off (attached air flow), it's a small almost triangle shape at the top of the window. It has a factory belly pan for the engine, I think the rear doesn't have one though. Wheels aren't half bad for areo, nearly flat with some styling along the edge. It's just the size, weight, and the fact it's a v8 that kills the mpg. If it was a stick I'd think I could hit 30mpg pretty easily with it, it holds gears way too long and doesn't hold gears as well as my corolla for loading the engine.

https://i.gyazo.com/46fef220a5391d8f...d9c02c1454.jpg

Here's a snow storm to give an idea of Michigan weather, this clearly is a more worst case type of storm, but it seems we get a storm atleast once a year that dumps 4-12in on us for 1-2 days. All of the video shows around the city, the country is plowed much less often, sometimes a week or longer after the snow comes down, like my road is a dead end dirt road. Also should mention, I can tell those guys aren't used to snow, they got stuck so easily, but I grew up in this stuff so I guess I have the experence. I've drove my corolla to work before dragging bottom all the way (for over an hour drive). When I got home I had a HUGE ball of ice built up from the engine heat melting the snow and refreezing to ice. The car had about 1in of suspension before the ice hit. Decided after that that if I'm dragging bottom, I'm not going for the trip unless completely required. Having a truck has been nice, I generally drive a car in snow if it's not too deep.

https://www.youtube.com/watch?v=wZV96Txp6D4

I should mention, I don't watch TV, news, and very very rarely on social media. I don't buy a 4x4 just because of the snow, it's just an added benefit of having one available. If the truck gets 25mpg with the mods and such, the cost of driving the current car is pretty pointless because I can drop the insurance and not drive it and only drive the truck and get a better savings. Clearly a better mpg car is a different story, just thinking short term on that.


@freebeard

Yea, pretty shocked how many replies in such a short amount of time. I guess it's a different topic than normal so maybe that's why it peaks more interest... like who in their right mind tries to get better mpg out of a big heavy diesel truck xD.

The bug deflector is a solid delete, never really liked them, but for some reason they are quite common. My dad's truck came with one too, I'm thinking the 2001 truck also has one, maybe it was a factory thing.

The hybrid setup is quite interesting, I just read the start of the thread, but looks like someone already did what I was thinking since an alternator can also be used as a motor, sounds like a larger motor was used in the thread though. I suspect the belt drive would be the limiting factor but I'm sure the thread goes into more details about attachment and such.

I also check my email often, so being the OP, I try to reply somewhat quickly.



@cRiPpLe_rOoStEr

I remember your user from way back when I was active on here. I'll have to look a bit more into the water injection systems. I saw some place (don't recall where) that it gave around 5% gains, does that seem about right? I think that was in context for a gas engine.

CNG is pretty interesting, I suspect the tanks are at pretty high pressures, propane runs around 100psi to get to liquid form. I'd think the propane systems would be a bit more established.

For water injection on a diesel, I suspect the concept is similar to a gas engine, cool the combustion chamber? It's been a long time since I read about those systems, and I always was looking at it from a gas engine point of view. Diesels seem to be so much more robust to mods, it seems to make sense to try things as long as I don't go to the extremes.

The video I watched about propane was talking about it with the priority of being more power, but the side benefit of good mpg too. He claimed with a fuel system mod, 4in exhaust (and gauges to monitor exhaust temps, boost etc), reflash style tuner set to +90hp setting, and propane, the engine put out about 600ft-lbs of torque at the wheels and the typical mileage was reported around 21mpg. I haven't looked into the fuel system mod, he only mentioned it in the video, but the guy specializes in powerstrokes and everything technical he talked about lines up with what I understand about diesels and my dad also agreed with what he was saying (ASE Cert mechanic). I don't need the extra power, but that should translate into getting even better mpg than the typical person that's beating on the truck using that 600ft-lbs on take off.

Anyway, CNG vs Propane (LP), I'm not sure if there's a place around me that refills CNG tanks. I can get tanks filled at a local gas station for LP, or if I get a nursing valve in a bulk tank, I could refill my own tanks and pay bulk price. To give a real world number, to refil a 20lb tank like a grill uses, it would cost me roughly $6.08, while the store near me that does tank exchange charges $20 (maybe it was $25, been a while since I used that service). I'm not sure what the gas station would charge, they use a scale to weigh how much LP you get and charge by the pound.

I keep making huge replies lol. It's a byproduct my tech background, I can type somewhere around 70-100wpm.

Anyway, thanks for all the ideas so far, I have so many directions to look into. It's always great having several options. If I can get my truck to hit into the 30mpg range while still having the capacity of using it as a truck (on and off road), I'm sure I could get my dad into cloning what I do to my truck and stop driving his Camry that gets around 30mpg and his T100 that gets around 17mpg (his rear axle pinion bearing is bad, it vibrates at lower speeds 5th gear, he doesn't drive over 70mph generally to hit 5th gear). I worked a deal out with him for a 3rd member to put in his truck, he just hasn't done the work yet.

... ok I'm getting side tracked again, better hit post before I get on 20 other topics lol.

[BLSTIC]

Originally Posted by ps2fixer

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?

Correct, I don't have them any more. The Mighty Boy was at 300,000km or something equally ridiculous for a carburettor equipped 800cc vehicle. The engine had a blown head gasket that entire time and may or may not have had a gearbox that did 5500rpm at 100km/h (no tacho). That car had no emissions standards. The Swift weighed in at 1000kg and was modern in every way. It's important to note that both cars were driven almost exclusively for short trips on a tight schedule in what was effectively the city and the driving was not particularly economical. The Swift could get as low as 5l/100km when I was on a road trip, with AC and lots of overtaking. This is about 47mpg.

[me and my metro]

No EGR on the 7.3 and the early ones did not have a cat plugging up the exhaust. Intercooler will help with power especially with a tune. There might be a mileage tune out there. I get 17 with my NA 6.5 GMC with 4.56 gears and a 30% overdrive. Gears would really help my mileage but I don’t have much power so rpm is king for me.

[freebeard]

He burns about 20 facecord per year, I burn around 12-15. Generally we are getting ash wood, so 1 full cord (3 face cord) weighs about 2880 lb dry or 4184 lb wet according to google.

It sounds like your best best would be to reduce the amount of firewood you have to haul. Do the math (miles carried) on how many BTUs in the fuel tank vs the truckbed. At about IIRC 50-60 miles you're better off to burn the diesel for heat.