How fo you know how much torque/rpms is enough for a somewhat fuel efficient car. I ve been trying to design somewhat fuel efficient cars. And I figured that torque iand Rev count are both important. I try for 1500s ~ for rpm and at least 100 NM to get 14 MPGs. However I also try to harmlessly decrease high/low end gearing to get better tow weights (Ive trying roleplay a truck. I found thay that all three 100 NM, 125, 150 all end up same amount 16MPGs = 8 or 7. I suspect its probably my gearing but I lowered the gearing and notice no change from the estmates on how many mpgs the car would have. I could try for more eco... but I doubt I could hit 28-32 mpgs at 2-3l at least not @ 1902. Its really strange considering on most occassion I find the estimate to be fairly accurate.... my 50 mpg engine at first becomes 10 mpgs (due to low power). If make the most powerful I-6 I can and leave low gearing/high gearing on high 7mpgs = 10mpgs... based on estismates and that's what if turns out to be.
Could it be my gearbox isnt "powerful" enough, I get that message even if I set the gear torque limit = to the motor's.
There isn't a way to know the torque amount needed to increase fuel economy. As there are many other factors that come into play such as the aerodynamic drag of the vehicle, the weight, so on and so forth.
In 1902, you shouldn't be getting 32mpg. Vehicles today are 5 times more fuel efficient than they were in 1900.
10-20mpg are average in this time period. And that's for phaetons and other very light runabouts. Less for bigger vehicles.
For instance a Ford Model T Pickup Truck should get between 13-21mpg. In 1915...
Now, as to how to raise your fuel economy.
1) Light vehicle and components
2) Reduce frontal surface area and make it more wedgy.
3) If you have low HP/Torque, then the gearbox needs to be geared more toward torque than fuel economy. The vehicle has to be able to move.
4) If you have high HP/Torque, gear the gearbox to fuel economy.
5) Top speed matters as some of the calculations are at a cruising speed of 100kmh. If you're vehicle doesn't go that fast, it'll calculate cruising speed at full throttle.
6) Don't expect 2016 fuel economy numbers in 1900. It won't happen, nor should it.
I'm not in front of the game right now, when I get back I'll upload a save game with a 1900 vehicle with great fuel consumption numbers.
My Mistake, Lower Gears, gear for fuel economy. Upper Gears, Gear for torque. If your vehicle has high aerodynamic drag (pretty much all old vehicles.)
Here is a 1901 Pickup, with 120nm (89ft-lbs) 22hp 4L I3. That gets 22mpg.
I dont expect modern numbers from 30s vehicles much less 1900 or 1910. As you probably even the model didn't have 40mpgs (25 in reality anf it wasnt made till a few after the car I intend to make) You however told me something helpful cruising speed. 2night Ill try with a top speed at or around 100 kph and see if I can reach closer to my mpg goal. The thing is not a predictable decline in mpgs some I get a gas rating as predicted i.e. 10 mpgs on the prototype panel = 10 mpgs with finished model... or a predictable 1/5 of what it is 50mpgs = 10 mpgs.
I however have managed 50 mpgs from a 2cylinder that (from the low torque and part weight) turns out to be 10 mpgs (gets me 2 or 1 1/2 stars on fuel) not bad for a a 125 engine.
But sometimes changes in gears has unforseeable effects. I.e. I try for 16 mpgs overall (give myself leeway of about 1-2 mpgs) and the amount turns out being 7 or 8. Ill try tweeking the top speed and seeing what happens.
Update*
Thanks for the example. I didn't think about it but it was the fact that I was using 1 gear vs 4 gears. 4 gears makes all the difference... I could probably go with a slower rev count, or lower torque but I figured 1500/100nm range was a good range (and a chasis that fits the appropriate engine of course.
The 4 gears made all the difference, and not reducing low gear rating. Not as quick or light as your truck (although that's not important with truck requests). I made the following, I found steam to be practically useless and heavy.
Here are my examples for posterity.
The expense ratios for my parts where
Chasis = %31
Engine = %45
Gear = %25
Truck #1 100 NM, 21 hp with 1.9 L I-5 17 MPGs
Truck #2 126 NM, 27 hp with 2.5 L I-6 16 MPGs
Truck #3 150 NM, 33 hp with 4.4 L I-6 16 MPGs
All engines were done as cheaply as possible with 1500 RPMs as a goal, 100,125, 150 Nms respectively. Only the weight (min) and rev slider are at max... with some slight fuel tweaking.