I defiantly stand corrected on the diesel efficiency at load, the member getting 50mpg was using P&G with engine off to get those figures and it sounds like since his focus went elsewhere he's getting around 35mpg with his current driving habits. Sadly no mention what has changed, but I'm guessing he's not P&G any more.
The coldest week in my area gets down to about -10F at night, so a block heater is basically a must around that time. I already bought a couple mechanical timers a while back for another project (off grid lighting in a shipping container I use for business storage) and the idea was to burn up the excess power from the solar to keep standard car/truck batteries topped up since I have a few spares around that I might recharge once a month or so. I generally get junker vehicles quite often, so I haven't had to buy a new battery except once to get a vehicle home.
The PSD (power stroke diesel) has a static turbo, so the peak efficiency would be interesting to investigate. It has no waste gate, 100% of the pressure is pushed into the intake. I suspect being smooth into the fuel rather than quick jabbing would be more ideal to let the turbo spool up as the load is increased (more fuel to take off for example).
The page I found on the atkinson cycle is quite interesting. Seems like the down falls (low rpm power output) could be offset by increasing the compression ratio for the shorter stroke on the compression stroke, but have the power stroke be the full length. At least the concept makes sense to me for gas engines. Not sure how well it would translate into diesels. Probably a bit more over kill than I'm looking for since the power stroke diesels are an engine designed to have a lot of bottom end grunt.
If I remember right, my corolla was making roughly 14hp to go 55mph. I thought it would be an interesting design to have a small engine,say 20hp for your cursing engine and a larger say 80hp engine for a small car that would lock in and fire up for take off power. Lot of dead weight but weight effects mpg so much less than a lot of other factors.
That reminds me, there was a user on here building a custom car with the ideal tear drop shape, 3 wheeled, and a small diesel engine to power it. I should try to dig up that thread, maybe there's some engine related mods that could make sense for me.
Capacitors and super capacitors are an interesting topic too, over on another forum we were talking about them for atv's with out a battery, but a way to get solid and reliable 12v dc power (technically 13.5-15.5v dc) through a regulator/rectifier. I suspect maxing out the alternator is no big deal as long as it doesn't build up too much heat. In theory, the alternator could be used for the regen brakes and also an electric motor to help with take offs. I'm not sure if there's enough efficiency in the required parts to pull something off like that, but for a 3-4 cyl car I think it could be a fairly large gain. I guess the question at that point would be if it would give better benefits over just deleting the alternator from the get go (or a disable switch).
Poking around some threads and such, it seems like there's only been 2 members that really posted much info about driving full sized trucks with diesels for mpg. Their mods were mainly air dam, grill block, side skirts, and I saw a mention of a belly pan and areo cap. The 2nd member had a 7.3L diesel like me so I have atleast a point of reference. They were getting around 26mpg which isn't bad and it looked like very minor mods. I didn't check but I'm thinking they had an automatic and the manuals are known for better mpg, atleast for the typical driver.
I guess there's two versions of the 5 speed transmission, I have to check the ratios and try to figure out which one the truck has. Basically mine has a creeper gear first, so take off is in 2nd gear.
Power Stroke Diesel Transmission Guide
It's the ZF-S5-47 about the middle of the table. Wide ratio vs narrow. Based purely on rpm and what I've read other people with the transmission had for rpm with 3.55 gearing, it sounds like mine should be the wide ratio (slightly higher geared over drive). 70mpg is dead on or just the tinyest bit above 2000 rpm, the other post I saw the person said they were around 2100rpm.
The truck is at my dad's place since he has an area to work on it, so I'm not 100% sure of the tire size. I know it's slightly wider than stock, something like a 265 75 R16. Yay math time lol.
1 mile = 5280 ft
70mph = 369600ft/hr, 6160ft/min
Tire diameter: 31.6in, circumference: 99.4in
wide ratio 5th gear, 1 rev of the engine = 0.3706 turns of the tire, or 36.8421 inches -> 3.0702ft. 6160/3.0702 = 2006.4rpm
close ratio 5th gear, 1 rev of the engine = 0.3658 turns of the tire, or 36.3636 inches -> 3.0303ft. 6160/3.0303 = 2032.8 rpm
They are so close, can't really tell the difference in 5th gear
. I guess the best test would be speed at 2000 rpm in 1st gear or if there's some sort of markings to id the two apart. I think that kind of confirms my rear axle must be 3.55 since the math lines right up with the tach and speedometer.
The heat storage system sounds interesting, I suspect it must use a fluid that has high heat capacity (generally highly corrosive with salts etc) and the bulk of the stored fluid is in a highly insulated box/container? This crosses over with some of the research I've done for rocket mass heaters, water is great, but adding a type of salt in it increases the capacity more, I think it has a lower freezing point too.
For the hybrids, my reading dates back to around 2012ish, so maybe in 8 years there's been some pretty major design changes and marketing focus. Newer vehicles always have to put out higher hp numbers to keep the average person wanting to "upgrade" their vehicle. I'm perfectly content with ~450ft-lb of torque at the flywheel on this diesel, I don't need the near 1000ft-lb of torque that the newer trucks have. If they took the updated tech and put it in half the size of engine to match the old machines, I bet some pretty impressive mpg figures could come out of them while still being a very solid power house for work. I've seen the same trend while researching GVWR. A 1 ton truck used to have a payload of 2000lbs, now they are something like 3 1/4 ton (7000lb) or more. In the 80's Toyota made a couple trucks that were badges as a "1 ton" but I suspect they were meaning it's payload capacity was truly 1 ton instead of the 1 ton "class" of truck.
Anyway, my wheels are turning in my head lol. If I can hit over 25mpg, then it would almost make no sense for me to have my car on the road. Not really an ideal mpg car, a 1990 Lexus LS400 with a V8 gas engine, RWD. I wanted to try one out and they are an awesome car, it's like 5x the quality of a Corolla if not more. I've been thinking of maybe getting a newer Lexus with a hybrid system, something around 2006ish. One guy I talked to with one was pulling pretty impressive numbers for a fair sized car, it was around 35-40mpg. With me driving it I'd think I could hit 45mpg pretty easily and make the corolla pointless to get going again lol. Of course the cost of the car isn't cheap, so the fuel savings won't pay for the car for an extremely long time. The corolla is rusted pretty badly, so it's only got probably 2-3 years for the body left.