We get some of our most interesting topics from reader questions.

Past questions include how emergency responders should react to hybrid and electric cars, and whether towing a Prius behind a motorhome is a good idea.

Today, we have a query about green cars (not trucks) that offer all-wheel drive. Our reader Stephen Fryer writes:

Will there be any non-SUV hybrids or diesels with all-wheel drive (e.g. Audi TDI with Quattro, BMW D with Xdrive) available in the U.S. in the next two years?

That's a great question, Stephen (we're big fans of all-wheel drive too). So, here's what we know.

AWD green cars: all crossovers or SUVs

2009 Cadillac Escalade Hybrid

2009 Cadillac Escalade Hybrid

Today, all clean diesel and hybrid models that offer all-wheel drive are crossover or sport-utility vehicles.

Among hybrids, the list includes the compact Ford Escape Hybrid, the mid-size Toyota Highlander Hybrid and Lexus RX 450h, and the now-out-of-production 2011 mercedes-Benz ML 450 Hybrid.

Then you can add the Volkswagen Touareg and Porsche Cayenne S hybrids, and the trio of full-size GM SUVs from Cadillac, Chevrolet, and GMC. There's also the unusual BMW ActiveHybrid X6, which its maker dubs a "sports activity coupe."

2012 Mercedes-Benz ML350 BlueTec

2012 Mercedes-Benz ML350 BlueTec

On the clean-diesel side, you have diesel versions of the BMW X5 and the Mercedes-Benz ML, GL, and R series vehicles.

Sedans: not so much

Among today's hybrid and diesel sedans, nary a single vehicle offers all-wheel drive.

The Ford Fusion has a AWD option for the gasoline version, but it's not offered in the Fusion Hybrid model. And the expanding roster of hybrid sedans from Toyota, Lexus, Hyundai, Kia, Mercedes-Benz, BMW, and others only power a single axle.

Ditto for diesel sedans from Mercedes-Benz, Volkswagen, and newcomers Audi and BMW: no all-wheel drive option.

Coming up ...

2012 Audi A6 live photos. Photo by Joe Nuxoll.

2012 Audi A6 live photos. Photo by Joe Nuxoll.

We think your best bet in the next couple of model years may be the new Audi A6, which will be offered with both a clean-diesel engine and a hybrid powertrain option.

And if we had to lay money on it, we'd expect all-wheel drive to be offered on the A6 TDI before the hybrid model.

Audi's Quattro all-wheel drive system is one of its distinguishing features, so it offers AWD on every model, including the compact A3 hatchback (though not an AWD version of its A3 TDI). That makes it more likely that an A6 might have both the green powertrain and AWD.

The issue, we suspect, is that all-wheel drive costs a few thousand dollars extra, and so does either a hybrid powertrain or a clean-diesel engine--meaning that the AWD green car ends up with a base price more than $5,000 higher than a gasoline model, perhaps pushing $10K more.

Is there a market?

That leads to the question: Do you think there's a real market niche for an all-wheel drive hybrid or diesel sedan?

Or do the buyers who want AWD green vehicles also need the added capability of a crossover or sport-utility vehicle?

Tell us what you think. Leave us your thoughts in the Comments below.


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