This has to be the all-time champion of evergreen conspiracy theories. I first heard this crock in the early 60s. Of course, never the first bit of corroboration.
2000 Ford F-350 Super Cab Pickup
4x2, 6 speed manual
Regeared to 3.08:1
4 inch suspension slam
Aero mods: "Fastback" fairing and rugged air dam and side skirts
Stock MPG: 19
Summer MPG: 27.0
Winter MPG: 24
Oh heck! It's certainly pervasive. I was in a training session at work on the subject of environmental issues, you could have predicted (and of course it happened) someone piped up stating that some friend's relative, while working for a big automotive concern, happened to invent a carburettor that got 100mpg or doubled fuel mileage or some such... and all rights to the device were snapped up by said big company never to be seen again.
I would be willing to do a lot of my driving at 35 mph if I could get 100mpg vs 45mpg driving 50-55.
So do it, already!
My ex-Passat (still in my name, but now it's 'hers') averaged 48 mpg in "normal" driving, but 80+ when really trying for good mpg and keeping speeds down to the 35~40 mph range. I strongly think your 45 mpg could be brought up to mid 70's by dropping your speed to mid-30 mph and concientiously driving for fuel frugality. Then you could claim to have a derivitive version of the non-existent big-oil-supressed, miracle mileage air /fuel mixer. Maybe not 100 mpg, but halfway there for absolutely free, no licensing, no infringement, no labor.
The down side is needing 14 hours for a 500 mile trip, now THAT gets tiring quickly.
You can get 100mpg with "Steam cracking". Do it in real time. 1 gallan of gas don't just = 48 Horse power per hour at 100% engine eff.!
Ok, I googled "steam cracking" and read the wikipedia article, and I get that steam cracking is the process of breaking down large hydrocarbons into smaller hydrocarbons. What does that have to do with automobile engines and their efficiency?