Not bad for an 1800 pound vehicle.

Another load of tripe. Doesn't anyone vet these articles?

There have been no independent tests done to confirm that any of the figures quoted are actually correct.

What exactly is the basis of speculation the claims made are wild or exaggerated?

I think it is probably the number of claims for wild MPG increases due to energy conversion add-ons which result in more energy out than in, or over-unity. And CR4 seems to get an inordinate lot of them. Understanding that no guest has yet made one in THIS thread (and that includes you), it is guests who most angrily defend such claims, usually. So forgive us if we don't care to spend much energy on wild claims, nor to be too welcoming to guests. Your presence as "guest" is CR4 policy, and I accept it. Some accept it less. And forgive us if we like to see some empirical proof, from an independent testing agency. Shoot, we are happy to see some design detail that will let US test it. And many of us work in and for labs that are fully capable of setting up the tests, and performing them to the latest standards. In fact, many of the labs we work in welcome the opportunity, for any attendant gain in training, efficiency, or just plain old knowledge. But most of the claimants get angry and give us numerous excuses for why they can't deliver design detail, are being artificially suppressed by (name your culprit, Big Oil, The Automakers, OPEC, or, the always favorite CIA and the ZOG!) (That's Zionist Occupation Government, for those of you not familiar with US Right-Wing Survivalist Extremist talk). All of that noise, smoke, and confusion tends to jaundice one's view to claims of great gain, where so many have spent decades, and millions of dollars (or whatever else), to prove, and improve, nothing.

All of that said, I don't see any reason to doubt that 75 MPG IS available from a system such as Mr. Parker's. After all, at 16 HP, and a max of only a little over 70 MPH, the 70 MPH achievable in calm air, and one presumes NOT while going uphill, with a modest acceleration of around 8 seconds to 60 (or so, I might have missed that point by a few MPH), he isn't asking for astounding mileage AND astounding power.

On the other hand, we've discussed at length, with input from people far more versed in the fluid physics of Hydraulic drives than I will ever be, the use of hydraulics in automotive power trains, and it seems to me that the most telling arguments against, to date, have been the lack of robustness in full-time, long-mileage applications due to fluid heating and attendant physical breakdown of hardware, hoses, seals, etc. Of course a lot of that can be alleviated with more expensive, and heavier braided hoses, higher quality seals, heat exchangers in the system, etc. but at the penalty of cost to build, and of weight. The first augurs AGAINST technical feasibility on the basis of cost to build/repair/maintain, and the second augurs AGAINST the MPG gains, and the performance (somewhat marginal, in my opinion, but I do a lot of long distance highway driving, cruising at 65-75 MPG, uphill and downhill, with, against, and across winds. So I definitely would trade mileage for performance that would get me there. 500 miles takes a LONG time to cover, if you have to do it very often. And a lot of my trips are twice that!) would suffer to boot.

Mr. Parker, in my opinion, probably DID reach 75 MPG, and might even win the 100 MPG prize, but I don't think the plan is technically feasible on a general consumer scale. And no matter how green we wish to be, until we can design the vehicle that will have high mileage, reasonable all-around performance, and good expectable life-span, I won't plunk down multi-thousand dollars on it, and I doubt that any one else is likely to, either!

Sorry, folks. Too much coffee. But if you take the time to read all that, maybe it'll slow everyone down enough to cool the flames a little, too!

I appreciate your candor an agree.

This project would not likely produce a touring vehicle; revert to the 60hp, though an individual requiring less in the way of creature comfort preferring economy, not averse of maintaining may have interest; a dollar saved is a dollar earned.

The tech used has been proven when employed in similar applications though not of actual transportation. 75mpg for commuting the average distance is 15-20 miles, so nearly a week on a gallon; ya there's a market for it. The frugality of a moped becomes a burden in wet or winter.

Dear Guest (if that is your real name)

I don't understand why my response is off topic, unproven mileage figures from unreliable sources don't help anyone, but they do confuse the simple souls who lack the know how to critically analyse the article.

You're not one of those are you?

Engineering is ultimately based in the real world.

Somebody should contact Mr Parker . . . he might actually contribute to this forum . . . Ernie.Parker@Hennepintech.edu

?

Good steer...

If Detroit would refrain from insisting we don't want simple economy we may progress.

Admittedly Mother Earth news is not a technical journal.

& the claims about mileage, aren't as important as the technology, not being a fully product.

Is the concept any good?

I like the 3 mode pedal : power, brake, glide

Thank you Garthh for submitting this.

There are many improvements noted, realizing the budget was likely non-existent which is often as much a mother of invention as need.

I applaud them...

So often in many circles ways of accomplishing tasks have been done one way for so long or often perspective is lost of these being only "one" way not "the" way.

A 60hp VW trans-axle would have put manufacture about mid to late 1960's, 50wt gear lube and figuring the geometry of the suspension. Realizing 75mpg or 50 holds my attention.

Sure analysis will be required at some point but let's give moral support if none other now, the future's bright

I think the article is quite good, and think the students, the teacher, and even the writer deserve kudos (often, what is written about these efforts is gibberish, and insufficiently detailed to make any evaluation re plausibility.) 75 mpg under the conditions quoted is a very plausible figure. The .9 gph would be spot on for an industrial engine running at a constant 12 hp, which would be about the output of this engine at its torque peak, where it is most efficient. (You'd expect fuel consumption to be .5 lb/hp-hr). The efficiency of the original VW engine would be much lower, because it would be much further from its torque peak, and therefore suffering high pumping losses.)

In the right sort of around-town driving, and assuming regenerative braking, the fuel efficiency could be even higher, because the average speeds are much lower, so less energy is lost to stirring the air around the car. The 75 mpg quoted is perhaps a bit higher than the car would get in an EPA highway test, but the article adequately described the test condition. Their car is really not fundamentally different than my 100 mpg Progressive Insurance Automotive X Prize vehicle (although mine is far more streamlined, of lower frontal area, electric rather than hydraulic, and half the weight).

(Mine is also is a plug-in hybrid, so most of the time it uses no gasoline at all -- but that is an independent matter from its basic efficiency on gasoline. My vehicle is obviously far more efficient than the Chevy Volt, which has advertised a 230 mpg figure despite the fact that it will really get about 40 mpg on gasoline. Most of the various measuring sticks used for plug-in hybrids are completely screwed-up in my view. They combine actual fuel consumption with an "equivalent" for electricity that relies on a particular driving routine, changes in which can change the calculated figure by several hundred percent. They all require a lot of "ifs" and explanation of the test conditions.

Far better, I think, to quote a figure on electricity: 10 miles per kilowatt hour for mine, 4 miles per kilowatt hour for a Prius conversion or a Volt, 3 miles per kilowatt hour for a Tesla, etc. Then quote a separate figure for gasoline consumption when the car operates in charge-sustaining mode: 40 mpg for the Volt, over 100 mpg for mine, etc. These figures square with current measurement techniques rather than coming up with a completely new and incredibly misleading yardstick. 230 mpg suggests incredibly high efficiency... but the Volt is of average efficiency for an electric car [there are hobbyist cars that are more efficient, and the old GM EV1 was substantially more efficient] and of slightly sub average efficiency for a Prius-class hybrid.)

Sounds semi-similar to the work of a couple of guys back in the late seventies or early eighties who were playing around with a continuously variable transmission that allowed a rather diminutive engine to run at peak torque RPM always and propel a then compact (I believe a Buick Apollo) around for about 60 MPG. Don't know what the final outcome of that one was either, but I think that transmission ended-up in my '95 Lumina with an alleged 4 speed automatic that would get me about 28 MPG.