[Big Dave]

Comments on Neil’s updated list:

Combining rounded front and active grille:
Keep in mind that litigation concerns mean that manufacturers have to design cars for the worst case scenario – prolonged idling in Death Valley in the summer without overheating and the air conditioning working OK. That said, the active grille is something the diesel pickup truck community has been crying out for. Diesels take forever to warm up without substantial load. Closing off the grille would allow for quick warmup and active opening would allow it to adapt to Death Valley conditions when needed and be more aerodynamic the rest of the time. Another thing to add: Normally closed ducted brake cooling inlets that open when the brake lights come on.

Sealing seams depends on size of the seam. General aviation people have found that gap seals work well on 150 knot aircraft but don’t really help 130 knot aircraft. So you see gap seals on Mooneys but not Cessna 182s. Cars are even slower so the gap would have to be enormous (the gap between pickup beds and cabs) to be worth bothering with.

Floor pans are OK, but you have to take under-body servicing into account. Don’t make the poor mechanic miserable or your repair bills will be astronomical.

More gear ratios are good and I’d add that the torque converter has to go. CVT works for small, low-powered vehicles but is a flop for anything bigger. The new dual-clutch sequential gearboxes are a step in the right direction.

LRR tires are good but keep in mind their lesser traction. I’d like to see rolling resistance coefficients more widely published.

I used to have a Pontiac Grand Prix that had a MPG display that was on all the time.

Tire pressure monitors are available on Hummers. How accurate they are…I don’t know.

I like the idea of video cameras to replace side mirrors but state and federal regulations would have to be changed to allow this.

Right now, I don’t see a lot of scope for lower coefficients of drag. People have expressed a preference for an upright seating position and that more or less dictates a “hedgehog” vehicle shape and few people are willing to live with the additional length that a true boattail requires.

Wheel skirts area good idea, but they service issues have to be addressed. A skirt will be hated if it requires ten minutes work to get it off long enough to check air pressure in the tires.

Lighter cars are possible, but with collision standards what they are, that entails a much more complex and expensive structure. Cars are at the ragged edge of being unaffordable as is.