I want to build a 100-mpg car (and I want it to look vintage)

[ProDigit]

My response to single seater 100MPG at 60MPH:

I used to mod my Honda Rebel 250. It could get 110-120MPG at 45-60MPH.
That being said, forget about getting 100MPG out of any gasoline vehicle that's heavier than 500LBS.

I believe the optimal engine is a 300CC engine, single or ptwin engine, geared in such a way that it would reach 2k RPM at 60MPH in final gear.


Take reference car 2550LBS 'Fiesta ST' with 1 liter triple cylinder turbo enigne, and ~45MPG real life avg MPG.
Or, the Mitsubishi mirage with their 1 liter NA engine 2000LBS, 50 real life avg MPG car.

Then look at the highest MPG motorcycle (a 125cc Honda PCX) netting 115MPG. The next best one would be a modified Honda Rebel 250CC, which could net 105MPG.

If you plan on making a dual wheel vehicle with a 300cc engine and an aerodynamic shell, you could actually still get 100MPG, but that's about it.
For a 3 or 4 wheeled vehicle, you'll probably be limited to 75-85MPG at best, unless you run it on a track, and can do with an acceleration of 0.1 to 0.05G or so.

Even a modified Honda CBR300R for MPG, could only net 85MPG at best.
(and that was with modified ECU, and max gearing change possible, hitting 3k RPM at 60MPH). In theory it could hit 90-95MPG if it ran at 2,5k RPM.
This engine lugs at 2k RPM.

Edit: Like mentioned in the beginning of this thread, a diesel might get the MPG you'd want, and if you're ok with no acceleration, you could even hit 120MPG. The Kubota engines are probably going to be able to get the job done, however they're not a very pleasant engine for that purpose.
They are pretty low power, and don't have much reserve (meaning, you'll run a pretty low acceleration down low, all the way to up top of the rev range.

[redneck]

Originally Posted by ProDigit

My response to single seater 100MPG at 60MPH:

I used to mod my Honda Rebel 250. It could get 110-120MPG at 45-60MPH.
That being said, forget about getting 100MPG out of any gasoline vehicle that's heavier than 500LBS.

I believe the optimal engine is a 300CC engine, single or ptwin engine, geared in such a way that it would reach 2k RPM at 60MPH in final gear.


Take reference car 2550LBS 'Fiesta ST' with 1 liter triple cylinder turbo enigne, and ~45MPG real life avg MPG.
Or, the Mitsubishi mirage with their 1 liter NA engine 2000LBS, 50 real life avg MPG car.

https://ecomodder.com/forum/showthre...xed-23497.html

850cc

Top speed 80+ mph

250.6 mpg at the Green Grand Prix in 2015.




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[sgtlethargic]

Originally Posted by redneck

https://ecomodder.com/forum/showthre...xed-23497.html

850cc

Top speed 80+ mph

250.6 mpg at the Green Grand Prix in 2015.




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I was reading a webpage that criticized the Locost MAX for having a tractor engine that likely put out a lot of emissions. If that's true, it defeats one of my purposes.

[ProDigit]

Originally Posted by redneck

https://ecomodder.com/forum/showthre...xed-23497.html

850cc

Top speed 80+ mph

250.6 mpg at the Green Grand Prix in 2015.




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I know shell made some crazy high MPG vehicle with spoke wheels, but that thing needed a fuel heater, and had zero to sixty acceleration probably longer than it took to read this whole thread!

[redneck]

Originally Posted by sgtlethargic

I was reading a webpage that criticized the Locost MAX for having a tractor engine that likely put out a lot of emissions. If that's true, it defeats one of my purposes.

Fractional amount of fuel used = fractional amount of emissions created

Nothing is emission free.



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[redneck]

Originally Posted by ProDigit

I know shell made some crazy high MPG vehicle with spoke wheels, but that thing needed a fuel heater, and had zero to sixty acceleration probably longer than it took to read this whole thread!

No spoke wheels. No fuel heaters or special gadgets.

Just a well thought out package.

The car accelerates normally and does not impede traffic.


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[sgtlethargic]

Originally Posted by redneck

Fractional amount of fuel used = fractional amount of emissions created

That's true, but too simplistic. Rates and what the particular emissions are, are important.

Nothing is emission free.

I've been wondering if it's possible to have a combustible fuel and/or system that cleans the air.

[aerohead]

I did some back-of-the-envelope calculations with the 2018, University of Michigan, NOVUM, solar racer, Cd 0.10, Af approx. 7.788-sq-ft, curb weight 420-pounds, Length- 196.0-inches, width- 38-inches, and height- 35-inches. 4.8-hp. top speed- 85-mph.
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I 'inflated' the car, growing to the height of a common, contemporary sedan, height= 55.5-inches, width= 60.25-inches, and length= 310-inches ( wow!)
Using a rough cubic displacement relationship, the weight would come in around 1625-pounds, with 19.145-hp, a 19.943-kWh lithium-ion pack, and 90mm Schwalbe 'Cruiser' tires.
I allowed an inflatable, 45.8-inch tail, to allow for garage parking. Top speed would be held to 85-mph. Allowance for 2.775-inch ground clearance ( air suspension ).
It would be 2-place. 1,975- pounds with two aboard.
Cd 0.10, Af 19.583-sq-ft, CdA 1.9583 sq-ft.
At 65-mph, the road load is 7.887=horsepower, 90.519 W/mile. 3.389-hours drive time to battery exhaustion, 220-mile range, at 371.76 mpg-e.
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A crude metric for ICE would be, figure 1/3rd the efficiency of a BEV, so with a gasoline powerplant, you might expect to see 124-mpg @ 65-mph constant velocity, with two side mirrors.
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For comparison, Dr.Paul MacCready of AeroVironment, estimated the 1987 GM Sunraycer at 400-mpg, if powered by an ICE powertrain.
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A streamlined, 2018 LEAF SV would be looking at 198 mpg-e HWY, and 235-miles range, vs 148-miles and 125-mpg-e.
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100-mpg is there for the doing. You just really got to want it. With BEV's it's no challenge at all.

[freebeard]

Originally Posted by sgtlethargic

I've been wondering if it's possible to have a combustible fuel and/or system that cleans the air.

Any engine will do so if the air is dirty enough?

[sgtlethargic]

Originally Posted by freebeard

Any engine will do so if the air is dirty enough?

On one hand I want to reply here and now; on the other I don't want to split this thread with this topic any further.