4wd vs 2wd
 

Hello, car novice here.

Can anyone tell me if there are any advantages to driving a 4wd vehicle in the city as opposed to a 2wd? Or rather, having a 4wd car in 4wd mode in the city? Does it affect fuel economy?

Thanks.

It effects economy bigtime, and there's no need to do it. 4wd is only for when there's not enough traction to use 2wd.

So if I had an SUV that can be set to either 4wd or 2wd, 2wd is best for fuel economy? Thanks, that's very good to know.

What DJ Happy said. Only need for 4WD in the city would be weather so bad public services can't cope with it... in which case, you probably need to stay home anyway :)

No, 4WD can be nice in slippery conditions. Just remember not to engage the low range, if you have one (its usually indicated as 4L on the shifter).

I'm curious, without judging, as to why you've chosen an SUV for use solely in a city?

not only is it best for fuel economy, but also for wear. No need to be wearing out the expensive 4wd stuff unless you actually need it.

Also read your manual to determine which setting locks the center diff - and then don't use it unless you're offroading and stuck bigtime - otherwise all 4 wheels are locked to turn at the same speed, which becomes a big problem for turning - things tend to break.

4wd is for low traction conditions ONLY!!! you will destroy your transfer case if you drive around on dry paved roads in 4wd unless your car/truck is full time 4wd or awd. If your vehicle has seperate 4wd ranges (4H and 4L) these are for high and low range, low range would be used for applications where lots of torque and not much speed are required (pulling people out that are stuck, rock crawling etc.) where high range would be for slick roads, mud, and situations like that. 2wd will give you better fuel economy by a small amount.

What they said, 4WD is only good in the city for snow covered unplowed streets and even then it's not always needed.

I've not. I live in a desert country and an SUV would come in handy for desert camping and so on. I was just wondering if it was worth changing it down to 2wd in the city.

I should also add that I haven't bought it yet, but probably will in the next few days.

If don't know if you should swith to 2wd drive in the city, I doubt you need the 4wd in the desert.

/thoughts

One thing to note; It's important that you use your front diff every now and again in order to keep everything well lubed and moisture free. Using your front diff at least once a month helps keep that expensive 4wd stuff in good operating condition.


Try driving around the city in 4wd with locked hubs and you'll clue in real quick that it's not a good idea.

Depends on the vehicle. Systems and ideal practices vary widely. What specific vehicle & transfer case?

I'll put this example straightforward, my mom owns a jeep grand cherokee with the v8 package and has the transfer case which is 4wd low or 4wd high only, the gas mileage with it on sucks bigtime 15mpg compared to about 19+ that other jeep owners get that have the transfer case with a 2wd option.

Again, systems vary.

Merker, you could swap your transfer case for an NP231, run in 2WD, and not see any improvement. I've done it on a number of Grand Cherokee's. You could pull the front driveshaft and still, no change. The front tires will still turn the front diff because your front hubs are always locked. That's the primary added drag of the system.

On the other hand, a true 2WD Grand Cherokee without a front diff will get a couple MPH better on average. Depends on driver, conditions, engine condition, etc. Those are the largest contributions to MPH differences between two otherwise similar vehicles.

To provide a good answer for the original post we need the vehicle model, year, and 4x4 system name. Anything else is presuming across systems that can be very different.

Gotcha. Being from the land of $1.50 a litre of gas, I still don't get that whole SUV in the city thing. For desert stuff I fully understand :) Have fun with it, and remember the cardinal rule in buying a new car: Test drive everything!!! :)

If you saw the way a lot of people in SUVs drive around here, you'd want to upgrade to a tank, but only because there isn't anything bigger and more heavily armored. Our problem is that we give licenses to anyone with a pulse and charge next to nothing for gas. I also have a theory that we'd have a lot less accidents if our cupholders wouldn't let the driver remove the cup while the vehicle is in motion.

$1.50? That's criminal. I think I must live in the cheapest country in the world for gas - about 20 cents a liter here.

Just for the record, I didn't buy the car as I ran out of money, but I'm hoping to get it in the near future. It's a 1995 Grand Cherokee and it drives like a dream.

Indeed, $1.50, depending on exchange rates. And, MrSelfDestruct, I fully agree on the low standards of drivers. It takes about 3-6 months of classes and driving instruction, as well as about $1000 to get your license here in DK. It makes for marginally better drivers. My main objection to drivers in general, is that they are too scared of their cars. There should be a mandatory course for anyone applying for a license, that teaches them the limits of cars. Here in DK, for ex., there is a general consensus that travelling at speeds in excess of 80kph on a highway when it rains will apparently lead to some sort of spontaneous combustion or some such... Bugs the hell out of me. I should start a thread about this, so we don't jack this one...

What about 2WD for driving up to the mountains in the snow? Is that especially dangerous, even with chains? I'm thinking about getting a small truck (Dodge Dakota or Chevy S10) and will probably stay in the city, except for some snowboarding trips in the winter.