Design Ideas on a car for primary highway use

[Bicycle Bob]

Originally Posted by RobertSmalls

But the EV1 had 21ft² of frontal area! No, I want the VW L1, Daihatsu UFE-III, or some sort of four-wheeled, tandem Aptera with a 5HP gas engine and a 30HP electric motor for acceleration, and a battery just large enough for a hill climb. I want all this, plus side airbags and intelligent seat belts.

After decades of cogitation, I think the way to get maximum economy with acceptable safety is to start with a full-body "helmet" in a streamlined shape. Add the heavy hardware at the front, where it will help stability in crosswinds. Use two front wheels for safe braking and better crash protection.

It isn't hard to wind up with a highway-ready vehicle that weighs less than the driver, when you start with a velomobile in mind. It can have a mononcoque body made of crash-helmet materials to give amazing crash safety, but it can still be run over by trucks or bounced off even a Metro, and of course those are the accidents that would make the news. For those willing to drive as if they were as invisible as wise old cyclists, I think insurance rates would be low, in a free market.

[rbrowning]

Originally Posted by jamesqf

Where do you find one of those? (Other than the '70s Toyota "Sport Truck") All the pickups I've driven or ridden in pretty much force a bolt-upright posture on you. Of course people are different, but to me that's quite uncomfortable.

But for this sort of commuting, it's hard to beat the original Insight. I spent a couple of years doing a 250-mile drive over the Sierra to the Bay Area. (Not every day, of course, about once every two weeks.)

The autostop also makes it pretty good in stop & go (freeway) traffic, once you master the trick of it, which is not to stop & go in lockstep with the car ahead, but let some space open up and smooth things out.

By far the best seat was in a 97 Expedition, the second best was a 2001 Silverado. The 2006 Impala feels OK around town but after 30 miles or so you start noticing that the hips and lower back a stiffening up. A co-worker had the same complaint and he had an upscale model with adjustable lumbar support that mine didn't. Another coworker didn't have a problem with hers and she was doing about 45 miles each way. For me the more vertical seating of a truck can't be beat if your feet are straight out in front of you. But maybe something like a "zero gravity" chair is very comfortable so there maybe a way to get recumbent. well supported and fit various sizes of bodies for extended periods of time and protect them in a crash. If I could design he car I would start with an Expedition seat and build a tubular steel cage (NASCAR safety frame) with a foam reinforced fiberglass body.

But that's just how I would do it.

[99LeCouch]

Find a 98-99 Buick LeSabre with the skinny tires and front bench seats. I get 34-35 mpg at 60-65 mph, it's comfy as heck, and it's big/stereotyped enough that folks don't give a second thought to passing me. Plus you can sleep in the back seat if you're short enough, and it will hold gigantic volumes of stuff. I've done numerous 12-14 hour car trips in it, and have arrived without soreness or stiffness.

Aerodynamics can be improved by making an upper grille block, weatherstripping the hood to the headlights and bumper, smooth wheel covers, and putting fairings in front of the front wheels where they jut into the airstream. The rest of the car is a blob with okay aero.

[zman]

I agree with cfq83 about trying to keep the car design realistic, people in the Economoding community are special; we sacrifice things like comfort and the horsepower dripping sex appeal of a vehicle to go further on a gallon of gas.

Then there is completely opposite mind set out there, people driving Suburbans with 40” lift or 500 hp Mustang GTs as their daily drivers.

But people who live far away from their work and are the stereotypicaly Toyota Corolla drivers might want to switch to a car designed specifically for highway driving as long as it still looked and felt relatively normal.

I think a small diesel motor sized specifically to maintain 70 mph highway speed with an electric motor assist during acceleration is a way to go. It would be nice to have a system which uses the waste heat of the diesel motor to charge the batteries for the electric motor and keep onboard electronics online.

[Istas]

First responder's first point is the major key. Aerodynamics. Completely smooth underside, no "rain gutters" on the sides of the front windshield, windshield wipers that are out of the airflow when off, no excessive grille openings in front, kammback design at the very least, covers over the wheel wells in back and, ideally, in front as well. Boat-tail design would be even better, as the Aerocivic has demonstrated. And an engine and drivetrain that are designed in tandem to get the absolute best efficiency at a designated highway speed, 55 mph would be better but 65 mph is probably more practical, so, somewhere along that spectrum (about 90 to 105 kph).

I'm amazed at how many cars with a main selling point being high fuel economy, neglect the rear wheel covers and even a partial undertray (specifically under the engine bay and directing air smoothly past the front wheel wells). So easy to implement, without really compromising on appearance.

That FuelVapor car looks interesting. However, even though I'm not an expert in the least, it certainly seems like they've made some aerodynamic sacrifices purely for aesthetic reasons. And for an ideal highway cruiser, there could be a lot less power, especially with a small frontal area and low drag.

The Loremo looks like a pretty good candidate, with a 2-cylinder turbodiesel netting a reported 120 miles per US gallon. But even that doesn't have rear wheel skirts. I don't understand.

[ALS]

The first question should be what MPG are you shooting for while traversing the highways of America.

35 mpg?, 40 mpg?, 50 mpg? 60 mpg? over 60 mpg?

Second how much do you want to spend getting X mileage.

We talking what car will get me what mileage? Or are you planning on building custom / extensive modifying X car?

Bench racing is easy when $ isn't involved.

Aero, weight, low engine rpms are the biggest factors for the best highway mileage. A Cd under .32 is a must, weight under 3,200 lbs, 2,000 rpms or less at 60 mph.

If you spend any real time on the highway two must haves is a very comfortable seat, and a nice stereo.

[rmay635703]

Actually despite aero if you are building your own
Small & Light gets good FE.

The easiest to find small and light vehicles around are mostly older foreign cars the smallest is Subaru 360 then various honda civics and a few toyotas.

A subaru 360 with a diesel motor and a boattail would likely net you over 100mpg, it gets 60mpg stock with a 2cycle gas and seats 2 confortably 4 unconfortably. Seats can be changed like anything if you want/need something specific.

It no lupo but you can actually buy one if you want, good luck getting a lupo.

If you want a new car your basically stuck with the hybreds offered and the Chevy cobalt/cruise whatever they call it.

Older cars have a much wider gamut and can be modified to do what you want.

Cheers
Ryan

[Frank Lee]

Originally Posted by Istas

First responder's first point is the major key. Aerodynamics. Completely smooth underside, no "rain gutters" on the sides of the front windshield, windshield wipers that are out of the airflow when off, no excessive grille openings in front, kammback design at the very least, covers over the wheel wells in back and, ideally, in front as well. Boat-tail design would be even better, as the Aerocivic has demonstrated. And an engine and drivetrain that are designed in tandem to get the absolute best efficiency at a designated highway speed, 55 mph would be better but 65 mph is probably more practical, so, somewhere along that spectrum (about 90 to 105 kph).

I'm amazed at how many cars with a main selling point being high fuel economy, neglect the rear wheel covers and even a partial undertray (specifically under the engine bay and directing air smoothly past the front wheel wells). So easy to implement, without really compromising on appearance.

That FuelVapor car looks interesting. However, even though I'm not an expert in the least, it certainly seems like they've made some aerodynamic sacrifices purely for aesthetic reasons. And for an ideal highway cruiser, there could be a lot less power, especially with a small frontal area and low drag.

The Loremo looks like a pretty good candidate, with a 2-cylinder turbodiesel netting a reported 120 miles per US gallon. But even that doesn't have rear wheel skirts. I don't understand.

Allow me to help: skirts aren't that big a deal.

[zman]

In response to ALS question about the limiting design parameters I came up with the following which would make it a realistic production car:

Target price equal to current mid range sedans. $17000 to $25000

4 passanger
Use as many stock parts as possible - steering, suspension, interior, wheels, exhaust, emmision, electronics, cluster - would be mostly components from current production cars

Unibody made from standard materials and standard manufacturing processes - welded sheetmetal and plastic components.

Power plant: currently avilable technology

Target range :500 - 600 miles

Target FE: 60+ at 65 mph

[TheEnemy]

Originally Posted by zman

In response to ALS question about the limiting design parameters I came up with the following which would make it a realistic production car:

Target price equal to current mid range sedans. $17000 to $25000

4 passanger
Use as many stock parts as possible - steering, suspension, interior, wheels, exhaust, emmision, electronics, cluster - would be mostly components from current production cars

Unibody made from standard materials and standard manufacturing processes - welded sheetmetal and plastic components.

Power plant: currently avilable technology

Target range :500 - 600 miles

Target FE: 60+ at 65 mph

I wouldn't put it past someone to be able to manage that by building it themselves. But to have something like that to be produced by an automobile company with labor overhead, bloated management, liability for any failure or defect, mandatory crash worthiness testting. There is just too much overhead for them to be able to get both the mileage and the price point.


As far as seats, they do make good aftermarket seats that are often more comfortable, safer, and lighter than the orriginals. Most places can even build the brackets for you. The seats I put in my Jeep are similar to the SS style, they are about 5lbs lighter each, and I am good for about 3 hours of off roading before I start getting stiff. The only draw back is the cost.

An example
Aftermarket Corbeau Replacement Bucket Seats for Cars, Jeeps, Trucks, Vans, Street Racing and OffRoad