While it is possible to get that kind of mileage using very light, very small, streamlined cars that in no way meet modern safety specs, even hybrids don't do that well, tank to tank.
How exactly would the government and fuel companies suppress a 'breakthrough' in mileage, especially these days with the internet? Considering that nearly all car manufacturers are strugling to meet CAFE requirements, they'd welcome with open arms a car that could get 70 mpg.
Fact is, unless you can build the engine out of materials that require no cooling system, and run with sufficient compression/expansion ratio at very low revs so the exhaust gas is barely above room temp, the maximum thermodynamic efficiency of the engine is pretty well fixed at around 30%. F1 claims a record of around 50%, but that's illusory, since they are counting the energy recovered by the turbo and regen braking. You can get into compound engines that recover some of the wasted exhaust heat, but then you pay in weight and complexity.
I'm gonna say that I doubt a 65 MPG VW.
Yeah my main car is a Citroen. It's a comfortable full 5 seater with 6 spd auto tranny (torque converter). Even big Americans will fit in it ok. It has mostly every conceivable extra fitted and pretty much drives itself. It has a 1.2ltr turbo charged 3 cylinder motor. It goes very much like the average petrol 1.6 to 2.0ltr car. My model goes 0-60mph in 9.1secs. Reasonable for it's size. It produces 110ps with 205nm of torque at 1500rpm. It's direct injection with offset crank for better efficiency, better power, lower cylinder wear. It also has a cat with ppf. It goes better than my Audi 2ltr petrol car. At 70mph it's revving at 2000rpm. redline is at 5500rpm. The engine needs an oil change every 16,500 miles or every year whichever comes first. It uses a fully synthetic 0-20 long life oil. Top speed is around 121mph. She has plenty of power on tap through the rev range especially in sport mode. There's a piccy below. The one in the piccy is not mine but identical to it, even the colour. And yes, I'm talking about Uk gallons and it's the average miles per gallon for a days journey, not the instant readout that I'm quoting. Bear in mind that most of my miles are on motorways where the car is mostly in 5th or 6th gear. Around town my car gives me an average of 44-48mpg. On a 400 mile run to Birmingham from my home on very busy roads of all kinds it returned 68mpg for the whole journey. I calculated that by pencil and paper after brimming the tank. It tallied very well with the cars own computer with just 1/2 mile difference in the figures. Cars over here, even converting to US gallons go further than your average US car. In addition, using my cruise control gives as much as 6-8mpg more over using the right foot. I guess it removes the slight but constant movements on the throttle that we all make as we drive. The cars own electronics controls throttle movement so much more efficiently, wasting less fuel.
Over here there are many many VAG group cars that will achieve over 65mpg. My Skoda Fabia easily managed 74-75mpg with a best of 79mpg. They even did an uprated diesel version of my Skoda that did 94mpg. It was able to achieve that to if you didn't drive faster than 55mph. It's a late Golf size car but slightly longer. It was a solidly built estate car.
Here's another piccy of my previous Skoda estate car.
Jim, surely you get some cars like this over there don't you?
PS. true story. While I was shopping with my wife I parked my Skoda Estate car in the car park. I was immediately approached by two bewildered American tourists, who were actually driving an identical Skoda Estate rental car. That's why they approached me. They asked me if I thought something was wrong with their car. "it was showing 71mpg on the computer screen"! "That's wrong" they said and "is it going to harm the engine to continue driving it"? I said "is that all it's doing. It should be getting much nearer to 80mpg"! It was the upgraded engined version that was capable of 94mpg. They were stunned and asked why they didn't get cars like that over in the States. Given that the performance of these cars is very very good, I wondered that myself.
Skoda Estate...uses largely VW Golf underpinnings and extended VW Polo floor pan but is better quality than VW overall
Last edited by Stromrider on Tue Nov 17, 2020 1:43 am; edited 13 times in total