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Tahoe/Yukon Hybrids: The 25 Percent Problem
3/15/07

It isn’t often that the red carpet at the Academy Awards brings us any hard news (apologies to Joan and Melissa Rivers), but Best Supporting Actress winner Jennifer Hudson made a surprise statement when she showed up in a prototype for the Cadillac Escalade Hybrid.

What was more news than the Escalade Hybrid itself, which should be available about a year from now, was the answer to a fairly pressing question about GM’s first true hybrids due to hit the road this Fall, the GMC Yukon and Chevy Tahoe Hybrids.  Since the first rumors of these vehicles, we’ve been expressing surprise and disappointment that, what seems to be a very interesting “two-mode” hybrid system by GM would net merely a 25 percent fuel economy boost over the conventional model.  Our suspicions were only heightened when GM announced that their first genuine Vue Hybrid, using the same two-mode drivetrain, would achieve a 40 percent boost over the conventional Vue.  Unfortunately, the Car and Driver article tells us exactly why:

Like the Tahoe and Yukon gas-electrics, the Escalade hybrid will be a two-mode hybrid that supplements GM’s venerable 6.0-liter V-8 with power from two electric motors. At low speeds, the vehicle can run on batteries only, the engine only, or a combination of both. At higher speeds, another operating mode engages the electric motors and the cylinder deactivation system for more efficient operation. GM claims that harmful emissions will drop significantly, and fuel economy will be boosted by some 25 percent compared with utes equipped with the 5.3-liter V-8.

So, GM is actually strapping their hybrid drivetrain to a more gas-thirsty engine than their standard conventional model Tahoe and Yukon models.  And any claims of “this is what our customers want” is sheer bunk, as out of the roughly 280,000 Yukons and Tahoes sold in 2005 (the last year we have solid stats on), over 70 percent of those vehicles sold had the 5.3 liter engine.  It seems the flagging sales of the Honda Accord Hybrid, a vehicle that made that same mistake by going with the six-cylinder rather than the more popular four-cylinder variety for its hybrid, didn’t teach GM much of anything. 

Muscle hybrids that don’t downsize their gas engines are enough of a waste of hybrid technology’s potential as it is.  To actually upsize the gas engine, then add the hybrid drivetrain for even added kick?  As my grandmother would say, it’s a shanda (roughly translated to from Yiddish to “shameful travesty”).

Of course, the automakers who have invested in the two-mode technology (GM/DaimlerChrysler/BMW) are just trying to play the, “look at the cool technology, aren’t we the greenest ones of all now?” game.  For instance, check out this article in the Delaware News Journal on the Durango Hybrid, which uses the same technology and promises the same meager 25 percent fuel economy boost.  Here’s DaimlerChrysler’s quote:

"It is a step above what is available in hybrid architecture," said Nick Cappa, spokesman for DaimlerChrysler. "This is likely to be the template for hybrid architecture."

Even if that were true, it’s far more important to use the technologies wisely than just to develop them, as we’ve seen with conventional vehicle technology over the past three decades.  It would be a shame to see hybrid technology go down the gas-thirsty sinkhole of “more power at all costs!”  It looks like GM and DaimlerChrysler are poised to learn yet another painful lesson by not breaking from their gas-guzzling rut.

Posted by: ScottN 3/15/07

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