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.

Ah ****, I just lost my reply- I give up.

My plan is to start with an old car and modify it to be shaped like the BOCruiser, choose an engine that produces the horsepower needed to move it at 60 mph near its maximum efficiency, and add a turbocharger for accelerating (if needed).

Hey wasn't there a guy who put a 3cyl kubota diesel in a metro and was getting around 100mpg?

What's a CHAdeMO?

Do you have the bodywork experience required to modify such a car to become more aerodynamic while maintaining that vintage car look?

100 mpg would require serious ecomods in a Metro. A metro is basically a far less aerodynamic Insight with a less efficient engine. The Insight can get 100 mpg up to ~50-55 mph stock. There is a thread about a seriously modded metro that supposedly gets Insight-like numbers (probably could do better than the Insight if it had the Insight drivetrain) here. Funkhoss averaged over 90 mpg for 90 days in his Metro, but that's with mods and serious hypermiling, not 60 mph driving.

Not yet.

I think you are thinking of changzuki's car
https://diesel-bike.com/Centurion/ce...cs_600x231.jpg
https://ecomodder.com/forum/showthre...xed-23497.html

There was a guy who did a kubota swap in a metro, but I don't think he ever got it on the road (atleast not that he mentioned in his thread)
https://lh3.googleusercontent.com/pw...-no?authuser=0

https://ecomodder.com/forum/showthre...geo-32945.html

And you've got the mechanical and electronics background to do that? Turbo selection; fabrication of the exhaust manifold, intake plumbing, intercooler plumbing; development of engine management, changing the fuel system and injectors - and so on?

Maybe I am pretty slow, but just turbocharging my Insight and fitting and mapping the engine management was, for me, a year-long project on its own.

And I have done turbo and electronics work on cars plenty of times before!

Thanks for not getting half done before asking for opinions. :)

Personally, I'd be most comfortable with a Beetle floorpan.

https://ecomodder.com/forum/member-f...ve12d2-509.jpg

https://ecomodder.com/forum/member-f...945-veyron.jpg

https://i.imgur.com/6SENw.png

The taper at the front compared to a Ghia/Type III pan will accommodate modern front wheelwells and a beam extender can increase the wheelbase by ~8".

https://ecomodder.com/forum/member-f...gt-one-tm1.jpg

To accommodate the rear engine follow Luigi Colani:

https://ecomodder.com/forum/member-f...ni-desktop.jpg

https://ecomodder.com/forum/member-f...-c-form-02.jpg

<airframe//powerplant>

You can put almost anything on a VW bellhousing. Pinto, TDI diesel, electric, & etc.

For a pure electric, the Lexus Highlander 68hp axle. For a hybrid boxer or inline three/four, the GM E-Assist serpentine belted 20hp altermotor.
______________

Else, clone Aerocivic.

It's a rapid charger.

It's a charging standard.

It won't necessarily be turbocharged, gasoline, nor EFI. My previous project was a propane turbo (non-EFI) 2.3 L Ford in a '61 Comet.

I know you like Bugs. If my brother would kick down the free Karmann Ghia he got 30 years ago ...

They're modular. My son gave away the Ghia I bought for him when he needed a car [in 2012].

But, '61 Comet? :thumbup:

Great!

(It was just that you said you wanted 'an efficient engine operating at its peak' and to get that, engine management is obligatory.)

this

do forget to knit your self some seatbelts
https://ecomodder.com/forum/attachme...1&d=1601628084

As mpg_numbers_guy said earlier, the Insight is a great point of reference. In stock form, using exreme LRR tires which sacrifice handling and traction, with the inflation pressure raised to 45+, and a few minor aero mods (partial grille block), the Insight is capable of 100mpg @ 50mph. As speed increases, that fuel economy drops significantly. I want to say that at 60mph, it's closer to 80mpg.

https://ecomodder.com/wiki/Vehicle_C...t_of_Drag_List

The Insight has a 0.25 drag coefficient (very low), a frontal area of ~20 sq ft (very low), and an engine whose peak thermal efficiency is just as good as the best from Toyota and Honda today (~40%) - albeit with a lower output than Toyota and Honda's current best.

My thinking is, you'll need an engine that is no less efficient than the Insight's, which is a very short list. You will also need to beat it in both coefficient of drag and frontal area. Diesel helps - the fuel contains ~15% more energy content, but you also usually pay more for it so it may not win in cost per mile.

If the goal is cost per mile per unit energy, going electric in an area with cheap electricity may be the easiest way to achieve this, but you have the upfront costs of the batteries.

From the Urban Centurion thread,

^ While that's impressive, drag increases with the square of the speed. Using a simple drag calculator, the drag at 60mph is 3x higher than at 35mph, while the speed has only increased by 70%. Meaning that, if drag is the sole difference between MPG at the two speeds (RR and mechanical loss stay constant), that 128mpg @ 35mph might be 75mpg @ 60mph. Still very respectable, but the decently aerodynamic Centurion with its 37hp-at-the-flywheel engine is still well short of your target.

Is there hostility in this reply?

Many 'do' was a typo and it's just incoherent otherwise?

100-mpg @ 60
 

See if you can find Doug Malewicki's 'California Commuter, or Alex Tremulis' Subaru X-100, both of the 1980s.
I abandoned my project simply considering how traffic behaved around me when on a motorcycle.
Americans are sociopaths by default. They won't follow at a safe distance and going up against a 3.5-ton projectile is more than I want to contemplate.
The guy who bought Three-Wheeler's 1st-gen Insight boat-tail is routinely seeing 80-mpg on the open road. And it's 5-star safety rated.
Pay attention to Julian's wisdom on this one! I've already lost a brother to an SUV. I don't want to hear about you.

That's a nice thought.

Build to pass a tech inspection at some race track, SCCA, NHRA, 24 Hrs of Lemons, etc.

Jack McCornack used to be on this forum.
 

https://www.motherearthnews.com/gree...r-zm0z13amzmar

It could be a starting spot.

I agree with FreeBeard about using the classic VW bug platform as it gives you a multitude of kit car choices for bodies. You can adapt various engines to fill your needs.

The suggestion of a diesel as your choice for an engine is a good suggestion to follow. The choice of a Kubota 3 cylinder does not give you much in the way of tuning but does give you a high starting point for thermal efficiency without much effort.

But, if I was you? I'd get a manual front wheel drive with a substantial overdrive and stick a Kubota 3 cylinder on it. Then I would cut off the back end of the vehicle and weld a substantial motorcycle frame and drive wheel on there. That back wheel will be electric drive and will provide a boost during acceleration to make your vehicle more enjoyable and safe to drive. Then build out the body in as streamlined a tadpole configuration as you can.

Or just contact R. Q. Riley.

https://rqriley.com/

Safety is a big concern. The centered seat is a part of that. I'm uncomfortable sitting right next to the door in my normal car. I want some wiggle room, if hit on the driver's door.

I'm also thinking I will include tubular structure in the body. Imagine the curved line of the aerodynamic streamlining template as a roll bar.

I've been looking at the mpg calculator. To reach 100 mpg at 60 mph the drag coefficient, frontal area, and weight will need to be minimized.

tubular structure
 

I'd recommend a copy of the Southern California Timing Association, or National Hot Rod Association, SCCA, rulebook.
They'll lay out chassis and roll cage construction to the Nth-degree. Gumby-79s working through the SCTA book right now for his attempt on the salt, once COVIDs behind us.
EASTWOOD Publications has many a reference on fabrication ,as does You-Tube

Then build a single or inline seater. No problem.
 

Starting with a classic bug chassis gives you the ability to skirt emissions regulations if it is early enough ('74 and earlier in my neck of the woods). Using a trike configuration allows you to register a custom design as a motorcycle in most jurisdictions.

Fiberglass over foam is easy to do at home with patience. It also provides significant strength and impact absorbing properties ( think surfboards and skis) requiring minimal steel/aluminum under-structure. Unless you really do want the extra NASCAR roll-cage.

yeah typo this laptop is from 07 the KB doe snot ork very well anymore... it's just the front room lapto for general use

One reason I'll be using a vintage car is because most California smog rules don't apply to them. If I put in a newer engine, then they apply, theoretically. I'm not trying to skirt smog rules- I want to do better than them by using an alternative fuel.

I don't want a full rollcage, just some decent protection.

I plan to work with metal. Freebeard's going to have to build the VW, at this time.

There was a time when using Beetle parts made more sense. Same with 2CV.

https://ecomodder.com/forum/member-f...-p1000641n.jpg

Braked and butt-welded Stainless Steel?

https://ecomodder.com/forum/member-f...11-5-38-12.png

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.

Vintage weight is probably going to be more of a killer.

Why? Modern cars are typically heavier than older ones of comparable size due to all of the modern electronic stuff added. A '60 Falcon weighs 2400 pounds. A '57 Metropolitan weighs 1750 pounds.

Vintage styling doesn't weigh any more than any other styling.

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