The boring actuarial types of the car insurance industry publish data at http://www.iihs.org/iihs/topics/driver-death-rates on “the number of driver deaths per million registered vehicle years.”
Set the form to “Very Large” and “SUV” and you’ll see that the 2WD Chevrolet Suburban has a death rate of 0-38 (confidence interval) whereas the 4WD version of the same car is at 11-67. (They also give you the actual number, but I think the confidence intervals are a fairer basis of comparison.)
The “large” SUV world also shows that the 2WD versions are safer.
For minivans they break out the Toyota Sienna 2WD (2-16) and the Toyota Sienna 4WD (1-37). [Note that the Honda Odyssey seems to be the safest minivan, with a confidence interval of 1-15, which is an upper limit lower than anything I found other than a couple of Lexus SUVs (0-12 and 0-14, which does raise the question of how meaningful the lower limit is; if it is 0 does that mean it is impossible to kill yourself, sort of like in Groundhog Day?)]
In the midsize SUV world I couldn’t find any pattern.
Readers: Want to look at this? How about the hypothesis that 4WD encourages people to venture out in bad weather? Is that supported by these data?
Sort it out by prevailing weather and terrain and then see if a new pattern emerges. I bet you not too many 2wd versions sold in mountains where driving is already considerably more dangerous.
4WD buyers might be more dangerous drivers. I bought a 4WD for climbing and fit in with the 4WD SUV is more dangerous profile.
Maybe the person, not the car, is the cause. Maybe people who fancy themselves as a more aggressive and capable buy 4wd.
As you suggest in the last paragraph, I expect risk compensation is probably a factor: https://en.wikipedia.org/wiki/Risk_compensation
For the Chevy Suburban, the 4WD model probably suffers from “Hey, hold my beer, watch this! ” syndrome.
The ’08 – ’11 Honda Ridgeline 4WD does pretty good against its competitors – third at a score of 13 (0 – 25). But it’s not really a 4WD even though the emblem advertises that. It’s a 2WD that automatically switches into 4WD when the vehicle senses it’s needed. But there is a way to lock in 4WD for low speed needs.
Yikes! My 82-year old dad drives a ’14 Camaro Coup – 55 (36-74) – and he has cataracts and can’t turn his head to the right! Should I be worried?
Check your source again for 2008 small pickups—the top five are all 4WD.
It is misleading to look only at the confidence interval and ignore the death rate. I’m pretty sure the confidence interval is to the death rate the way a first order effect is to a second order effect; that is, any rational being would prefer 10 (1-39) to 20(1-39) in any universe.
Like in the statistics of small aircraft, the selection bias of human factors dominates the characteristics of the actual vehicles; those who chose Cirrus against aircraft with similar performance have a statistically higher tendency to use/maneuver their aircraft more aggressively and/or less skillfully.
When you brake, there is no difference between 4-wheel drive and 2-wheel drive.
The kind of folks who opt for the 2wd version of a vehicle with AWD available are the kind of people who don’t drive at night or above the speed limit.
I wouldn’t have a lot of “confidence” in these numbers.
For example, if you look at large luxury cars, the BMW 535i has a lower death rate 0 with confidence interval 0-36 than the BMW 528i (20,4-60). These are identical vehicles except the 535i has a bigger engine, so you would expect the death rates to be the same or higher for the more powerful vehicle, but the results are the opposite.
I’m guessing that in general, more 4WD cars get sold in northern states with more bad winter weather and that explains why they do worse. It’s possible that overconfidence in 4WD causes people to go out in bad weather but I’d guess that the main factor is that they sell more 4WD cars in Colorado and more 2WD in Florida.
The main factor in stopping/maintaining control on slick roads is your tires (you want snow tires for snow, studded tires for ice). Traction/stability control is the 2nd biggest factor. The number of driven wheels is not a big factor at all. The main thing that all wheel drive does is that it will get you up an icy hill when 2WD cars won’t. Now on the way back DOWN that hill, your AWD doesn’t do a thing – all cars have the same 4 wheel brakes. Now maybe you are better off NOT climbing that hill because now you have to deal with going down it.
There must be some mindset of 4WD owners of “I”m taming nature in this beast!!!” whereas perhaps 2WD owners are more interested in just having the SUV form factor.
Reminds me of snowy bumper cars in Utah, although there’s a full assortment being wrecked there:
Statistics don’t lie but boring actuarial types do?
I had issue with otherwise great Ford 4 wheel drive auto mode – suddenly was on highway section covered with black ice and SUV went sideways. After righting it without issue, switched to 4 High gears and drove slowly without issues. To make 4 wheel drive auto reliable 100% time trucks need to be equipped with remote sensing of road condition. With traction control modern two-wheel drive cars are safe in regular condition but way more likely to get stack when weather changes. Technically it will not show as a road accident in safety statistics.
The Small SUV category is pretty evenly balanced between 2WD and 4WD. I’ll expose my personal biases and suggest there is something about people that choose Large+ SUVs?
More seriously, Andy is probably onto something pointing out that more 4WD vehicles are sold in areas prone to difficult driving.
Boring actuarial type here.
I was interested in your question, so I pulled the data out of the IIHS website to have a look at it.
For SUVs and trucks, driver death is about 20% less frequent in the same model with 4WD than with 2WD.
I didn’t look at other classes of vehicles, since there weren’t very many where they split out the models by 2WD and 4WD.
Interestingly, 4WD seems to make smaller SUVs safer, but makes larger SUVs less safe. Since 4WD adds about 200 – 400 lbs of weight to the vehicle, maybe there is a “sweet spot” of weight that makes an auto optimally safe?
There is obviously a lot more that can be said on this topic but without any further analysis I am inclined to say that the answer to your question is “no.”