UKH

Hi,

We're looking at one of these as our next car, but Volvo seem to have changed the drive train earlier this year from front wheel drive to rear wheel drive.

We're trying to work out why they changed and what the pros and cons of each are? Front wheel drive are generally better in snow and so on, but are we missing anything?

Thanks,

Probably parts sharing across the range or better packaging since I'm guessing it's not sold on its performance/dynamics.

RWD with big torque as electrics develop stops the steering fidgeting and evens out tyre wear. Much nicer to drive in general IMO. Electronics tame the low traction driving these days.

Jk

It'll be to do with where the battery and electric motors most easily fit in (which affects production costs) and weight distribution (for better handling).

RWD generally gives better handling (or maybe it would be more correct to say it makes it easier for engineers to design a better handling car) - can't remember the technical reasons for this but there must be someone on UKC who knows why.

As many have said on previous threads, winter tyres and correct driving technique make a bigger difference in most snow conditions than FWD/RWD/4x4.

Edit: from Wikipedia "In 2023, the single motor version was revised by adopting the rear-wheel drive layout instead of front-wheel drive. It is the first rear-wheel-drive variant of a Volvo vehicle in 25 years. The revised version received a new motor, resulting in improved range and efficiency."

Yes, that's pretty much my thoughts - mainly manufacturing costs.

Good point about the high torque on electrics - maybe torque steering was an issue on the earlier versions. We are looking at the single motor rather than the twin motor version, though, so probably not such an issue, but they've consolidated the number of chassis variants.

Doubt it'll make much difference for our usage, though.

Yes, definitely changed from FWD to RWD on the Recharge. Probably took the FWD petrol/hybrid version as the basis and are now refining that.

I just edited my previous post - answered my own question from Wiki 😁

The XC40 was the first car on a new platform - these things cost vast amounts of money to develop so it would have been designed with all sorts of possible configurations in mind.

The pros and cons of front or rear drive are traditionally dependent on the engine being in the front of the vehicle. Hence the hype of a lot of  supercars being mid engined and so better balanced. 

With electric cars a lot of weight in the batteries so easier to design in a well balanced car for either front or rear drive.

With a lot of power on FWD, the front lifts under acceleration limiting how much power you can put down. The grip goes to the back.

Also the more you ask from the wheels the easier they slip. They can steer or accelerate well, but compromised if you ask them to be both at the same time.

Also torque steer I assume is still a thing on EVs? They may have engineered it out by now but it's where the power fight with the steering pulling the car one way or the other.

RWD is just better.

FWD is only better in snow if you have an engine up front putting weight on the wheels. The concepts of old don't apply any more.

Of course one needs winter tyres in proper winter conditions. A training course for good winter driving technique is also a very good idea, because some of it is not intuitive.

Given the above, FWD vs RWD vs 4X4 makes quite a big difference. I personally much prefer FWD over RWD in winter conditions (e.g., in Canada with snow and ice on the roads for 5 months), and 4x4 is  superior to both. The only snag with 4x4 is that, if one skids (which is rare), its a 4-wheel skid, which is very nasty - it's like having a rug pulled out from under one, and there is very little one can do except take one's foot off the accelerator and hope for the best! Most of the time, though, one feels much more glued to the road with 4-wheel drive than with 2-.

Interestingly, amongst the very worst "off-road" vehicles in both summer and winter conditions are American RWD pick-up trucks. It's almost unbelievable how bad they are - in stark contrast to the image projected by the adverts.

Have read a few reviews and torque steer was significant with the FWD versions. Not a problem for a lot of drivers but it does seem a lot of BEV drivers use the instant torque / acceleration. Tyre wear on fronts reported higher especially if torque used around corners scrubbing the outer edges.

Going RWD has apparently allowed Volvo to change battery supplier, increase battery capacity and therefore range and put in their own newly in house developed higher torque/increased efficiency motor (both FWD and AWD got larger more efficient motors).

I agree about instruction on winter driving being useful, I was taught by a rally driver how to drive in snow in rally prepped Saab 96. Admittedly this involved going extremely fast with lots of left-foot braking sideways action, none of which should really be applicable to normal driving on public roads. It's arguably made me over-confident in snow, though I have done thousands of miles on snow, mostly far too fast and I've only screwed it up once (see next para). I've grown up a bit and am slower now.

I also agree about pickups, I wrote off a HiLux in the snow a few years ago, I was in RWD, had no load in the back and had off-road rather than winter tyres on it. It has to be said that I was driving too fast, it wasn't impossible to drive it in the snow without resorting to 4WD. I also ran a BMW for many years and had no issues driving it all over the Highlands in snow, with winter tyres on. It behaved differently to FWD cars but overall I never wanted for traction especially up steep hills and   it was a lot more controllable than any FWD car I'd driven. 

A lot of people get obsessed with traction and being able to get going. That concern really should play second fiddle to being able to steer and stop.

I once many years ago aquaplaned (on aqua, coming down the A590 dual carriageway past Kendal in summer so not a slow speed incident) which of course is a 4 wheel slide. As you say, bit scary, foot off accelerator, get the wheels pointing in the right direction and hope you get grip before things get nasty (I did)

It would appear the myth about front wheel drives being better in snow is incorrect 😁

youtube.com/watch?v=P8Ck_zXa19A&

I'd say it just gets misused or misunderstood rather than it being a myth.

In that video both cars have decent weight distribution so the driving wheels on both have similar load on them. Add the winter tyres and it makes sense that the rwd performed best. Both cars could get acceleration with the grippy winters so could load the rear tyres.

But, take an old 205 which I'm guessing has 65% of its weight on the front wheels, if using summer tyres it's going to perform better than any front engines rwd car on summer tyres.

So there is merit to fwd cars being better on snow, but only for front heavy cars.

But there are so many other factors to consider. Put a friction plate LSD on any rwd car and it will perform better than pretty much any open diff fwd car.

Not sure I get this. Do you mean wheel spin under acceleration?

Don't think he does, surely it's just that a 4x4 has more grip than a 2WD, so the speed at which it "lets go" for any particular circumstance will be higher than when a 2WD lets go hence bigger (negative) consequences.

Also, when a 2WD "lets go" it's usually just the back end or occasionally the front end and the other wheels still give you a chance (maybe) to do something. With a 4x4 it means you've lost all 4 wheels so you can do nothing about it until/unless some grip returns.

4WD gives you more traction but not necessarily more grip. Some 4wd systems, I'm not sure which, can cause the car to crab sideways in a strange and not particularly controllable manner on cambered surfaces. Mine (VAG haldex system) is great in the snow but if there's any major sliding around I feel like a passenger. However, this is never an issue if driving appropriately to the conditions.