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

[jjackstone]

Originally Posted by mpg_numbers_guy

Electric vehicles aren't free mpg. To convert to mpg properly you have to consider the cost of the drive rather than the watts involved. For most people electric vehicles are more expensive to drive unless you can charge them at home cheap or have access to free charging.

True. But if we do the conversion, you have about 33.7 KWH/ GALLON of gas. So if a gallon of gas cost $3, then a kwh would need to cost about 9 cents to be the same cost as gas. Most of the country has higher electricity costs than that especially California. However, a "gallon" of electricity will get you two to three times as far a gallon of gas. So your cost per mile varies more with where you live .

Originally Posted by mpg_numbers_guy

For example, a person I talked to would spend $5 to charge their Prius Prime battery, for 25 miles. That's $0.20 per mile. At 60 mpg in hybrid mode and $3/gallon running on gas would be $0.05 per mile, making electricity 4x as expensive, giving them an equivalent mpge of 15 mpg, even if the Prius readout claimed "199.9 mpg".

Wow! Someone was silly enough to pay almost 60 cents/kwh. Prius Prime battery is about 9 kwh. Additionally I'm pretty sure that the Prius is capable of charging the battery while it is running. Flawed logic in your mpge calculation. Mpg vs mpge is a physical number. The cost per mile is a separate issue as I showed above.

Originally Posted by mpg_numbers_guy

Vintage vehicles are typically larger and less aerodynamic. A few models were produced for aerodynamic efficiency, but would be hard to find. And it would need to be smaller or more aerodynamic than the already crazy efficient G1 Insight. Drivetrain could be from a G1 Insight, but then you'd have to fabricate custom mounts, etc. for it. There's a guy on here who swaps Prius drivetrains into classic cars, but his projects take a very long time.

Aerocivic.com might be worth checking out.

JJ

[JulianEdgar]

Originally Posted by sgtlethargic

Thanks for all of the replies. Notice how they are mostly stemming from the human negativity bias?

I try not to be negative but what you're discussing is a monumental ask - good safety, better fuel economy than almost any car ever made, needs to be based in some way on an older car.... it's just starting to sound impossible.

It certainly would be impossible for me!

[Fat Charlie]

It's not about styling, it's about weight. Pick any random small car today and any random component on it is going to weigh less than its counterpart on a Falcon. Like the frame.

It'd be great to design and build your own car, but it's a horrible exercise in efficiency. Your best move is to start with something small and efficient and turn it into something even better. Weight reduction, aero and powertrain work can do amazing things without forcing you to design and build your own suspension- or make do with heavy vintage suspension.

[freebeard]

Thanks for all of the replies. Notice how they are mostly stemming from the human negativity bias?

You'll put your eye out!

100 mpg at 60 mph. What do you think it would take to accomplish this? Single-seater, center-steer, possibly mid-engine, probably a 4-cylinder.
[snip]
I plan to start building, building my skills, and experimenting. I already know more or less what I want and what I want to work with.

Sounds like a Formula V or Formula Ford race car with safety barriers strapped between the wheels on each side.



Here's the powerplant pic I couldn't find for Permalink #18 (could be mid-engine in a race car frame):

[sgtlethargic]

Originally Posted by JulianEdgar

I try not to be negative but what you're discussing is a monumental ask - good safety, better fuel economy than almost any car ever made, needs to be based in some way on an older car.... it's just starting to sound impossible.

It certainly would be impossible for me!

Most, if not all, car makers' main goal is to make the most profit possible by selling as many cars as they can. They do that by appealing to things other than fuel economy and environmental awareness. Their engineers' limits come from these sales requirements. I am not limited by these; I am limited by physics. The physics says that the drag coefficient, frontal area, weight, and engine are the four main variables I can work on minimizing. If I minimize the first three, then I can minimize the last one, and probably still have decent acceleration.

How many miles per gallon did the VW XL1(?) achieve? How many miles per gallon do you think the BOcruiser would get with an ICE with its 0.135 drag coefficient? How difficult would it be to copy the BOcruiser? Maybe they'd send me the CAD files.

I'm shooting for 100 mpg at 60 mph, in the long run. It'd be something if I achieved 60 mpg at 60 mph.

[sgtlethargic]

Originally Posted by Fat Charlie

It's not about styling, it's about weight. Pick any random small car today and any random component on it is going to weigh less than its counterpart on a Falcon. Like the frame.

It'd be great to design and build your own car, but it's a horrible exercise in efficiency. Your best move is to start with something small and efficient and turn it into something even better. Weight reduction, aero and powertrain work can do amazing things without forcing you to design and build your own suspension- or make do with heavy vintage suspension.

What modern cars weigh less than 2400 and 1750 pounds like the examples I gave do?

[sgtlethargic]

Originally Posted by freebeard

Sounds like a Formula V or Formula Ford race car with safety barriers strapped between the wheels on each side.

That offers very little collision protection. I might as well ride a murdercycle.

[freebeard]

www.theweek.co.uk: F1 'halo' cockpit safety device is 'least worst option'



https://can-am.brp.com/off-road/us/en/shop.html

It may be your least worst option at 1750lb. A 2nd-hand chassis is a place to start.

[M_a_t_t]

Originally Posted by sgtlethargic

And I want it to look vintage.

100 mpg at 60 mph. What do you think it would take to accomplish this? Single-seater, center-steer, possibly mid-engine, probably a 4-cylinder.

I love the looks of the *BOcruiser. And the Phantom Corsair. Hudson Hornets. This custom Metropolitan (they weigh 1750 pounds).

You asked for opinions, negativity bias or not, those are the responses.


100mpg, of course is a large task from scratch. Obviously we don't know your background very well. Anything is possible. The way I see it (I have dreamed of a similar project goal) is do your best and make it a work in progress. If 1.0 gets you 40 mpg at 60 mph then make revisions, maybe it goes to 65 mpg, if you keep at it you can hit 100 mpg. But it's gonna take time, effort, and dedication.

If you are thinking about this like I am for my version of this project then I think it's best to just get started. Do something. Sketch a design. Make that aero body and put a stock drivetrain in while keeping in mind what you think your ideal drivetrain is. This way you can aero test and get some mileage with the suspension setup to make sure there are no issues.

Once the shell is road worthy you can also do aero testing and make body revisions. Then you can go back through the project and cut out everything you said you needed, but in reality never used.

I think the biggest thing to remember is that it is your project. Anything anyone says (even if they are directly telling you to do something) is a suggestion. One of the biggest things I like about projects is messing up (assuming no one gets hurt and low financial waste). They provide a great story for me and remind me that version #1 is usually never the best option.

This does remind me of this thread though. You might find it interesting. I actually reached out to him on another forum that he is active on and he never responded. https://ecomodder.com/forum/showthre...cle-19863.html

The point of a project is to have fun and learn something.

I typed a response to what I think was needed and realized I was basically describing the VW L1 (not XL1).

[JulianEdgar]

Originally Posted by sgtlethargic

Most, if not all, car makers' main goal is to make the most profit possible by selling as many cars as they can. They do that by appealing to things other than fuel economy and environmental awareness. Their engineers' limits come from these sales requirements.

Sort of. Fuel economy has been a major sales point of cars for decades. It's the main reason that cars are now slipperier than ever before.

I am not limited by these; I am limited by physics.

Not really. You'll be most limited by cost and what you can build.

The physics says that the drag coefficient, frontal area, weight, and engine are the four main variables I can work on minimizing. If I minimize the first three, then I can minimize the last one, and probably still have decent acceleration.

Sure - but a lot easier said than done.

How many miles per gallon did the VW XL1(?) achieve?

Up to 260 US mpg.

How many miles per gallon do you think the BOcruiser would get with an ICE with its 0.135 drag coefficient?

I have no idea! What engine? What transmission? etc

How difficult would it be to copy the BOcruiser? Maybe they'd send me the CAD files.

I thought safety was important?

I'm shooting for 100 mpg at 60 mph, in the long run. It'd be something if I achieved 60 mpg at 60 mph.

Those two different figures are light-years apart in diffculty!