[Joxster]

Really nice report guys! Well done! I thoroughly enjoyed reading the technical differences that were well explained

Originally Posted by katchkamalesh

OT: I see a white Renegade in the top left corner in one of the pictures.

Was it trailhawk as well? Any info on that model?

Originally Posted by Samurai

Not sure which pic. I only saw Wranglers and Grand Cherokees, other than the Trailhawk and normal Compass.

I guess katchkamalesh is referring to this picture, and that is indeed a Jeep Wrangler, not a Renegade.



Cheers

[katchkamalesh]

Originally Posted by Samurai

Not sure which pic. I only saw Wranglers and Grand Cherokees, other than the Trailhawk and normal Compass.[/ATTACH]

My bad. Probably it was a wrangler.

I was referring to this picture.

Also regarding the Hill Decent Control (HDC), this system applies brakes momentarily and once the wheels are locked, the brakes are released. I don't think that it will have an adverse impact on the ability to steer the vehicle.

I also believe that this system will not allow the wheels to get locked because this system works in unison with ABS.

[cool_dube]

Finally Thanks for the wonderful review, Samurai!

Just to be sure I understood the various off-road modes correctly, here is a summary - please review and let me know wherever I misinterpreted:

• Auto - front wheel drive with torque transfer to rear axle if system detects any slippage in front wheels. Car starts in 2nd gear.
• 4WD lock - torque transfer to both axles (ratio?). Car starts in 2nd gear.
• 4WD low - torque transfer to both axles. Locked in first gear.

Also, a few queries:

• Can I engage all the 4 modes (snow, mud, etc.) with 4WD low or is the latter reserved exclusively for rock mode?
• Rock mode - What does it explicitly do? Is it just another variation of gearing/braking combination, akin to the other 3 modes, to better suit rock crawling? Also, does engaging the rock mode automatically toggle 4WD lock and 4WD low?
• Is the auto-braking-to-improve-traction feature exclusive to Trailhawk or is it available in Limited 4x4 as well?

[Samurai]

Originally Posted by katchkamalesh

Also regarding the Hill Decent Control (HDC), this system applies brakes momentarily and once the wheels are locked, the brakes are released. I don't think that it will have an adverse impact on the ability to steer the vehicle.

Not sure about HDC, but wheels were locking up plenty when coming down with brakes. You can see in the descent videos, where wheels are locked up.

Originally Posted by cool_dube

Just to be sure I understood the various off-road modes correctly, here is a summary - please review and let me know wherever I misinterpreted:

All correct.

Originally Posted by cool_dube

Also, a few queries:

• Can I engage all the 4 modes (snow, mud, etc.) with 4WD low or is the latter reserved exclusively for rock mode?
• Rock mode - What does it explicitly do? Is it just another variation of gearing/braking combination, akin to the other 3 modes, to better suit rock crawling? Also, does engaging the rock mode automatically toggle 4WD lock and 4WD low?
• Is the auto-braking-to-improve-traction feature exclusive to Trailhawk or is it available in Limited 4x4 as well?

My memory is fading a bit now. But I think you can apply 4Low at all the modes. That is why it is a separate button.
Yes, rock mode applies both 4Lock and 4low. Rest is ECU logic.
Yes, it is available in Limited 4x4 too. IIRC, Duster has the same feature. All traction control systems work on similar principle, when they have open differential.

[ARAY]

Thanks a lot for the Technical drill down. It was a bliss to read through the math you took time to explain. I guess this is what makes TeamBhp, TeamBhp. Beautifully explained while covering the minutest of details.

[whitemm550]

Awesome write up, as usual Samurai, thats what make me your biggest fan.

[Mar21]

Thank you for the crash course on the workings of the 4*4 !

Do they conduct events for customers ?(like the RE /HOG rides)

[cool_dube]

Originally Posted by Samurai

All correct.

Thanks, Samurai. Going by this review and feedback on on-road dynamics from multiple quarters, the Trailhawk appears to be a very tempting proposition, barring a few cons, listed below:

• P-R-I-C-E! An on-road price of sub-30 lac would have done wonders to the sales chart and made this a much better VFM proposition
• Less than ideal approach angle and GC (laden) for a competent off-road machine
• Less than ideal crawl-ratio but should do for most practical scenarios
• An auto-box that needs getting used to
• Relatively less real estate for it to don the role of a family tourer

I am sure many out there are waiting for those discounts to start showing up

[Arjun Reddy]

Thanks Samurai for the detailed review. Rated 5*.

Could not have had a better explanation of the differences between the Thar and the Trailhawk.

A few photos of my Trailhawk. Have clocked close to 1500 kms and enjoying every bit of it. Looking forward to a trip to Courtallam in sept to take it off road.

[psispace]

Thank you Samurai and Blackwasp for this wonderful review.

The technical aspects of it's off-roadability is exactly what I was looking for in reviews. Haven't come across such a detailed review anywhere else in India. Western reviews were skeptical off it's ability and felt it under-powered. However, the units they reviewed had the 2.4 petrol with similar bhp, but only about 230 Nm torque.

Staying where I am right now, I am really tempted to get one of these to reach places were my low GC Volvo won't go. And maybe sometimes go off the beaten path too.

Although a Thar would be fun to go off road with, the family wouldn't find it any fun. The only other similarly capable vehicles I can think of are the Force Gurkha and maybe to some extent the Duster AWD (properly modded). The former even has front and rear differential locks ! Though these cost only half as much as the Compass, they won't offer the same level of sophistication and comfort.

Would be interesting to have a comparison between these vehicles.

For those who haven't seen it, heres' an interesting comparison with the upcoming Renegade (in Trailhawk guise). Although its' two years old, its' still relevant.

https://www.youtube.com/watch?v=QlppU7Re5_M

[tomraven99]

Thanks for giving such a detailed explanation. So basically its the same system which is found in the Duster, or XUV AWDs with a misleading "low range" title being given. The 1st gear ratio of the Duster AWD is similar at 4.45.

[vinair]

Originally Posted by Samurai

Among 2WD vehicles, the RWD makes better offroader than FWD. That is because while climbing, most weight is on the rear wheel, and very little on front wheel. What is the point in having all the torque in the front wheel, which will have little traction? Therefore, FWD vehicles suck at offloading

Is this true? Thought it is the other way, where with just the driver in the vehicle, a RWD vehicle has less traction compared to a FWD wherein the engine weight provides some needed traction on the driving wheels.

[padmrajravi]

Originally Posted by vinair

Is this true? Thought it is the other way, where with just the driver in the vehicle, a RWD vehicle has less traction compared to a FWD wherein the engine weight provides some needed traction on the driving wheels.

He was talking about inclines in the above post. In a steep incline an RWD is better than FWD. Ussually FWD vehicles will have to be reversed up the incline. But when it comes to flat slippery or slush conditions, FWDs have an advantage with the engine's weight and possibility of steering input on driven wheels. Cars like Harrier with independent brake control and ESP will beat RWDs in those conditions.

[Samurai]

Originally Posted by vinair

..with just the driver in the vehicle, a RWD vehicle has less traction compared to a FWD wherein the engine weight provides some needed traction on the driving wheels.

That is the case only when the vehicle is on level ground or facing downhill. You don't need much torque to move when you are in level ground or facing downhill.

Where do you think the weight will be when the vehicle is facing uphill, when you need all the torque you can get?

Even when you are on level ground, if you want to take off faster, most weight shifts to the rear. This is why most sports cars are RWD.

[nishkamm]

Originally Posted by Samurai

The Mahindra Thar has open front and rear differentials, but the front and rear propeller shaft are locked together in 4WD mode. Therefore, if one tyre in the front loses traction, the front propeller will deliver very little torque. Instead, all of the torque will be delivered to the rear propeller, provided both the rear tyres retain traction. Similarly, if one of the rear tyres loses traction, all the torque will be delivered to the front propeller. That means, if any one tyre loses traction, Thar turns into a two-wheel drive vehicle. If one tyre in both the front and the rear lose traction at the same time, then the vehicle is a sitting duck. This happens often enough on offroad trails. Drivers often overcome this by using momentum, or putting weight on the slipping side, etc. Therefore, driver skill becomes very important in mechanical offroad vehicles.

Hi Samurai, Very nice and detailed explanation of the how the four wheel drive works in Thar and the Jeep Trailhawk.
One query though. Does the latest Thar (post Aug 2015) not have an automatically locking differential in the rear. How does it fare compared to the Trailhawk's mechanism of applying the brakes automatically and releasing them when required?