I am the lone occupant of an elephantine GMC Yukon full-sized SUV, a $56,045 festival of body roll, leather seats and satellite radio roaring down the 405 Freeway at 80 mph-plus.

Saudi oil sheiks are dancing jigs at my conspicuous consumption of their dinosaur juice.

Or perhaps not, because I am driving a GMC Yukon Hybrid, the fuel-sipping savior of seals, spotted owls and dewy-eyed ducklings. Not that my political correctness is going unsung, what for the 13 "Hybrid" emblems splattered on every exterior surface of the vehicle.

So even though I am using three steroidal tons of steel to propel my 190 pounds of protoplasm down the road, I have earned the right to be smug about driving an SUV on Earth Day.

General Motors has done the full-court promotional boogie to promote its jolly green giants. It brags about how the Brobdingnagian Chevy Tahoe -- the Yukon's twin -- was named "Green Car of the Year" at the Los Angeles Auto Show. It conveniently omits that no Toyota or Honda hybrids were eligible because repeat winners aren't allowed.

Decals you can't miss

Then there are those gigantic "Hybrid" decals: 3 inches tall across the door panels, with still more stickers on the windshields, plus metallic emblems on the quarter panels. You might as well just scream, "Please don't scrape your keys across my painted flanks, oh greener-than-thou Santa Monica eco-warriors."

Because it really has come to that. Around L.A., these incredible hulks are becoming so despised that many folks are hiding their atmosphere-killing gas hogs in their garages. The yellow Hummer H2, once as common as a California poppy in spring, now is a timid rabbit, peeking around corners rather than storming through red lights.

With hundreds of thousands of units of factory space reserved for these behemoths, GM is trying to play the green card. After all, Toyota used the Prius to paint green its whole franchise, including the thirsty Tundra pickup and Sequoia SUV, so why couldn't it work for GM? And if you are going to be trundling four kids and their gear, the cute little Prius won't quite cut it.

Haul ass and save gas. Sounds good to me.

Then again, we're talking about a hybrid SUV whose tailgate seemingly weighs as much as an entire Prius. But when GM brags about the Yukon Hybrid having 50 percent better fuel consumption than a standard Yukon, its otter-friendly sales pitch starts to fall apart.

Pocketbook sense

In a week of driving a Yukon Hybrid 4wd with a 6.0-liter V-8, I got 18.4 mpg on L.A. streets and highways. That's spitting distance from the 20 mpg claimed by GM's PR department. But it is equally close to the efficiency of a base Yukon with a 5.3-liter V-8 engine, which gets a claimed 17 mpg in the combined driving cycle.

This is far short of the efficiency gains reported by drivers of the Prius and Civic Hybrid. Heck, even the Toyota Highlander and Ford Escape crossovers get 7 or 8 mpg better in hybrid mode.

So I'm not quite sure what bonus I was receiving from the Yukon's hyped "Two Mode Hybrid," aside from the 13 SUV-validating decals.

In driving something nearly $15,000 more expensive than a base 5.3-liter 4wd, I was getting 1.4 mpg improvement. That makes about as much pocketbook sense as the summer gas-tax vacation.

What it really comes down to is not the price of gasoline per gallon, but the price to fill the tank, and how often it happens. The price per gallon doesn't matter so much as the grand total when the gas nozzle goes click.

In refilling the Yukon Hybrid's 24.5-gallon fuel tank in San Pedro, the gasoline pump's digital display passed the century mark. Not by much. But seeing the pump's readout hit triple digits made my stomach queasy.

A hundred smackers to fill a vehicle with a range of 450 miles.

Let's do the math. If your daily solo commute is from Santa Clarita to downtown -- a common slog -- you're churning a 75-mile round trip every day. That's a fill-up once a week, not counting errands, the Radiohead concert at the Hollywood Bowl, or your kid's soccer tournament in Fontana.

By the end of the month, the bill to fuel the Yukon might be as steep as financing the vehicle itself. That's the wrong kind of green.

GM better hope the Chevy Volt and other more earth-friendly hybrids get here quick, because Ed Begley Jr.-educated Californians are likely to see the Tahoe and Yukon hybrids as a shallow act of greenwashing. It would be a shame to see GM's entire hybrid effort tarred by its conciliation to SUV drivers

After all, re-arranging "General Motors" spells "Green. Or almost."