The hydrogen car! Gas-electric hybrids! Save the Brazilian rain forests! It seems that Detroit’s public relations machine gets greener by the week. Why, our socially responsible friends at General Motors tell us they have gone so far as to design a new military truck with increased gas mileage for the purpose of waging environmentally friendly war. Over at Ford, they’re happy to say they’re writing office memos on recycled paper.

Good for them. At least somebody there is thinking about the future.

As for the here and now? Well, we have to take an elevator ride from the PR department up to the executive suite. Here, the thinking goes in a different direction, naturally. This headline from the Wall Street Journal last week summed it up pretty well: “U.S. Auto Makers Blast Proposal on Fuel Economy.”

When it comes to today, rather than the dreamy tomorrow, Detroit still won’t budge. Not even a piddling 1.5 miles per gallon on their profitable SUVs and other so-called “light” trucks. The government proposed tightening fuel economy standards for these vehicles from 20.7 miles per gallon to 22.2 for 2007 — four years from now.

Nope, can’t do that. The future belongs to tomorrow, and that’s where it should stay.

According to a 127-page pleading by General Motors to the government last week, this meager 7 percent savings in gas and pollution would cost 105,000 jobs! SUVs would have to be made lighter, and therefore they’d be unsafe! And stripping off the weight would add $275 to the cost of a vehicle! All that and GM would still lose a staggering $1.1 billion, or almost $5 for every man, woman and child in the nation!

That’s the official company line; never mind the PR hype about someday “alternatives.”

Really, haven’t we heard this hysteria before? Say, for the last 35 years? First it was the safety nuts who were going to ruin the U.S. car business, and now it’s the environmental lunatics.

In an interview in 2000, William Ford Jr. offered a glimpse of Detroit’s fossilized thinking. When he was named chairman and chief executive of his namesake company, Ford directors took him aside for some counseling about his earlier friendships with environmentalists — “I was told: Stop messing around with these crazies.”

It’s cynical, but it works, this play on fear. Throw some tonnage on the highways and back it up with millions in advertising. Then have motorists figure out how to survive. What good is a clean environment if you get beheaded on the freeway? Let the consumer decide.

Before you big-iron types sit down and bat out your furious rebuttals, telling me it’s none of my business what you drive, let me say, you’re right. Even Robert Redford can’t resist an SUV, can he? Good example, Bob.

Yes, I’ve suggested that SUVs drive in truck lanes at restricted truck speed limits — for safety’s sake. But that’s just good-natured needling, and I’ll do it again. After all, let’s admit that half the time in urban America the speed limit is a laughable dream, and the remainder of the time hardly anyone seems to pay attention to it.

However, a word of advice: “Light” truck manufacturers and aficionados have a stake in the future of the breed. With stigma spreading, these machines will either get more efficient and less deadly to other motorists or their drivers will find themselves accorded the social standing of cigarette smokers or peeping Toms. Even Detroit’s PR departments can’t help you then.

Meanwhile, let’s acknowledge something else. This is going to be a long argument. For every family that comes to its senses and realizes it doesn’t need 3 tons of 4WD , there’s a junior executive out to prove that he won’t be shoved around by busybodies. He’ll move up to a Hummer out of spite, just to carry his golf clubs.

So in the meantime, will the civic planners and property developers who mark out parking spaces quit torturing us, please? If 52 percent of new vehicles sold are trucks, how about sizing up 52 percent of the parking spaces to accommodate them? We ought to give them this much: SUV drivers ride too high in the saddle to read those little painted words, “Compact Only.”