Off-Road Traction Assist Switch is apparently "Tarmac Mode"

[Surfyo]

I was watching a review by Chasing Cars on youtube: Mazda CX-5 turbo petrol 2021 review | CX-9 2.5 punch in a RAV4-sized SUV | Chasing Cars

At about 12:45 the reviewer starts talking about the "Hill Climby Car Button" which apparently works in a "sporting sense" and refers to it as "Tarmac mode" which will preemptively send power to the rear wheels rather than detecting slip and then sending power rearwards.

Based on what the guys says, I am sure someone might be tempted to try and use Off-Road Traction Assist for spirited driving.

Sounds like a bad idea. I assume this will cause premature wear on the clutch packs or break something else if used long term?

Does anyone on here use that mode in normal conditions?

 

[youri]

Interesting, but that is about as wrong an interpretation of that mode that you could get. There are a lot of review on Youtube of that off-road traction mode and that is not how it works at all ( you just have to watch off road tests for the cx-5). What it does in very short summary is apply the brake on the slipping wheel to ensure powers gets routed to the wheel that isn’t spinning (left to right, not front to back). It is trying to mimic a closed differential that way. But it isn’t designed for road use and it takes a lot of wheel spin before engaging, not really something that would happen on tarmac.

 

[Pitter]

Thank you for that clarification and important that you noted it does not apply front to back. I have tried turning off the TCS on occasion when in a situation where one front wheel is spinning and the there (appears to be ) no drive to the others. No difference with TCS turned on or off. I suspect Mazda's "Off Road Assist" is unrelated to any true positraction system. I had a pickup with rear positraction and the problem was the rear wheels had to spin to engage it. With that you were already pretty well bogged, The reality is that the only system that can move you forward with one wheel spinning freely is one that locks front and rear drive axels. Won't happen on CX-5s or any other family SUVs.

 

[youri]

@Pitter, I know I have mentioned before that TCS off was the same as the Off-road assist mode (and I still believe it is in some earlier model before the introduction of the "Off-road assist nomenclature like the 2018 CX-9). Your experience seems to indicate otherwise, which would mean that the TCS off in your vehicle does not attempt to simulate a locked differential like Off-road mode does.

There is no questions this system cannot beat a true locked differential (or positraction as you said), but it should be able to get you moving once a wheel is in the air and spinning freely. Skip to the 12 minute mark of this video to see the comparison with off-road mode on and off. 2020 Mazda CX-5 Off-Road Test and Review

 

[youri]

The mazda off-road traction mode works by applying the brakes in the same fashion as explained in the first Open differential portion of this video.

What Is The Best AWD System?

What's the best AWD vehicle? What all wheel drive systems are best? How do differentials impact the AWD system? This video looks at open differentials, locke...

youtu.be

Nothing ground breaking, subaru and other manufacturers have been using this method for a while.

 

[Pitter]

Thanks I've seen that video. I guess that system would have moved the car forward in my spinning wheel situation.

 

[hal2]

I've read reports in this forum that in slick condition, even rain, and hard acceleration, that the amount of quick accelerations grip/lack of spinning, is about the same whether turned on or off.

 

[dougal]

I've read reports in this forum that in slick condition, even rain, and hard acceleration, that the amount of quick accelerations grip/lack of spinning, is about the same whether turned on or off.

Actually I would say the opposite - at least for the pre-2021 models. On my 2018 CX-9, I found that turning the TCS off would greatly reduce front wheel spin in the rain.