AWD mpg

[02V70]

I have a 2002 V70 Cross Country, meaning it has All Wheel Drive. I was looking up the fuel economy, and it seems to be only 1mpg less than its two-wheel drive counterpart. Is this true? I thought all-wheel drive cars had much worse fuel economy. For reference, fueleconomy.gov says, my AWD volvo gets 17mpg city and 24 highway, and a FWD volvo gets 18 city, and 25 highway.

[vtl]

Your AWD system has a viscous coupler, which "turns on" only when the front axle starts to slip, i.e. there's a difference in front/rear tires rotation. Under most of conditions, it is a FWD car.

03-07 are different, they have Haldex Traction, which is proactive, but the car is still heavily FWD-biased. It is not a full time 4x4.

[02V70]

So the front tires would wear more then, right? Also, does that W button for wet and snow make it closer to a full time 4x4?

[vtl]

AWD wears out front tire more, yes.

W is for "Winter": it tells the TCM to use third gear from stop, to avoid immediate traction loss and wheel spin. And somewhat relax reaction to the accelerator pedal.

Volvo's civilian cars have no classic 4WD, never had, best to my knowledge.

But you don't need 4WD. Haldex Traction, tuned by Volvo, is very good. It makes Toyota's A-TRAC feel shy, though it uses the same principles and similar hardware. Of course, your model year does not have Haldex yet, but do you really need smart AWD in California? Also viscous coupling is much more reliable, that's granted. Haldex is PIA to service and repair, honestly.

You can get your car stuck far deeper in mud/snow when you use good tires with proper inflation (air them down). Say, stock Toyota Tundra TRD Offroad can make only maybe 50 feet more than XC70, with similar tires, like General Grabber A/TX on Tundra and BFG KO2 on XC70.

[02V70]

Cool.

Of course, your model year does not have Haldex yet, but do you really need smart AWD in California?

Where I live in California (far north, and near mountains), I would need AWD since it snows quite a bit in winter, and I like to go on steep-ish dirt roads to get to hiking trails.

Does my era of Volvo have the kind of traction control that brakes the wheel with less traction to do better in snow/offroad?

[vtl]

Yes, it does.

[abscate]

None of these cars are off-road vehicles. That’s just for the marketing shots. They drive well in snow with respect to good traction, with snow tires , and good braking , too.

[vtl]

This is at XC70's max: plowed thorough about 10" of snow before it started to high-center way too often and make me beer-thirsty.

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[Blacklab467]

Mine averages 9.8 liters per 100 Kms, 2003 XC 70. Combined city and Hwy driving. Remember that winter fuel where its cold has a blend and additives that reduce the Btu's per litre/gallon so the fuel mileage will suffer in the winter, much more so for diesel fuel. A highway trip in the summer may see as low as 8.9 litres/100 kms. That's the best I've seen on mine.

[vtl]

In winter air density is higher = more resistance. Oil and lubricant more viscous = more pumping loss.