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

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).

What would it take? To do a good job, and achieve the results you want, probably US$50,000 and 5 years - and that's from a starting point of being very good with your hands and having all the workshop gear and space.

(I base these figures on the real-world construction costs of a - much simpler - Lotus 7 replica.)

I used to think about making my own car (and I have the workshop tools, space and most of the skills) but then I figured a Gen 1 Honda Insight is a far better outcome than I would ever achieve.

I'm glad you were the first to reply. What would it take technically? Very aerodynamic, an efficient engine operating at its peak, lightweight, etc.

What mpg does the Insight get?

To be honest, I think it would take an incredible amount of effort.

So, how are going to get drag low - and build the body? Hand-beaten aluminium? Fibreglass and moulds? And how are you going to know it's low drag - bespoke models in a high speed wind tunnel?

How are you going to keep the engine operating at its peak?

etc etc

Manufacturers have the best engineers around and spend literally billions developing new models.

How much did the Volkswagen XL1 cost to develop? And I bet they amortised basically none of that development cost - and each car cost $144,000.

To be brutally honest, developing a proper car that matches your requirements I think is nearly impossible these days for a private person. At least, for one without a lot of money and time to spend.

A dead standard Insight can do about 84 US mpg at a constant 60 mph (no pulse and glide, etc).

A vintage looking car isn't going to have the aerodynamics to get great mpgs.

I think you might make it by using mpge rather than mpg. Yep, put an electric drivetrain in it and triple the efficiency. Then you could use the vintage format but do a retro version that decreases the drag to no more than 0.24. You implied you could go with a single-seater so it doesn't appear you are worried about the size. That means you have the capability of keeping the frontal area very low. If you insist on carbon fuels I would go with a diesel engine where legal and use a form factor like Dave Cloud's Dolphin.

JJ

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.

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".

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.

Some people are dumb.
If you are not charging at home or some place that is free and paying to charge you are spending nearly as much if not more than what you would spend on gasoline.

It will if it is small enough https://www.youtube.com/watch?v=ww6r...nel=KDawgFilmz
https://www.youtube.com/watch?v=tAYY...=RickBlekestad

Drag coefficient is only part of it, frontal area is too. If you are building a car and it has to look old then it is hard to have both old look and low drag coefficient.

A car with four wheels and two seats? A kit car with a fiberglass body powered by a 3 cyl. diesel would be the simplest. If you want only a single seater then streamline a smaller motorcycle, 250cc Honda liquid cooled, as those in the Vetter Challenge.