[speedguy]

Originally Posted by Sankar

What do you say regarding this?

"It is with these dangers in mind, that ARB’s engineers approach the subject of fitting bull bars to such vehicles, with the concern being that fitting a rigid structure, not behaving the same as the original frontal characteristics of the vehicle, may change the deployment timing of the air bag."

http://www.arb.com.au/ask-arb-air-bag-compatibility/

Anyone reading this planning on installing a locally made bull bar. Don't expect for the airbags to function normally once you have them on. If you must, buy a properly made and tested unit either OE or quality aftermarket who has done the testing.

Really nice article. But I fail to understand some contradictory points. Like:

That is not to say that ARB has developed useless bars that do not offer the vehicle any protection. ARB air bag compatible bull bars do provide significant protection for the vehicle whilst also offering functional winching capability on winch mount versions.

If it is not offering any protection, then these bars are useless. If it is offering any amount of protection, then how are they tuning in harmony with OEM?

There are lots of 'it may affect' or 'it may reduce' terms instead of some concrete researched facts!

Please don't think I am in denial mode. I just want to understand these things. I am working in an OEM right now & as per our understanding accelerometers does not get affected by these bull bars.

[sourabhzen]

Originally Posted by speedguy

Saurabh, accelerometers are non contact type. Irrespective of their position they can identify deceleration & sends signal accordingly.
Anuruddhus has posted nice write up regarding this. I hope it clears many doubts regarding airbag deployment.
Please note point number 2, where role of accelerometer is explained

Fair enough. Some may interpret the information otherwise and install the bull bar but I will not take that chance. My vehicle booklet also advice me against the same.

[speedguy]

Originally Posted by sourabhzen

Fair enough. Some may interpret the information otherwise and install the bull bar but I will not take that chance. My vehicle booklet also advice me against the same.

OK. As a matter of fact it is correct. But if Tata is advising not to fit bull bars, then they should not keep this as official accessory also. From pure mechanical engineer's point of view, I don't think it is possible to affect functioning of airbag.
Let's play safe & not install anything which may affects our safety.

[Sankar]

Originally Posted by speedguy

Please don't think I am in denial mode. I just want to understand these things. I am working in an OEM right now & as per our understanding accelerometers does not get affected by these bull bars.

When i asked for a front bull bar for my Crysta the dealer said Toyota does not approve of installation of any front bars for the airbag equipped vehicles.

Accelerometer may not be affected by front bullbar, but does it affect the way crash forces are dissipated around the passenger compartment? This is a concern in non airbag equipped vehicles too.

I am not working for any OEM, i bought a product and the manufacturer who made this says don't install bullbar on airbag equipped vehicle. But on the other hand a fellow tbhpian who's working for the manufacturer or maybe for the vendor supplying the kit to the manufacturer says bulbars don't affect safety (airbags are for safety). I'm confused

[rshnvjy]

I think we are all missing the point here.

Modern cars are designed by their respective manufacturers not only to pass stringent frontal and side impact crash test norms, but also to be compliant with pedestrian impact norms. If you notice today's cars, they all have fairly deformable front bumpers and plastic grilles which give way if we try pressing them with our thumbs. The front of the car has specifically been designed to spread impact force over as large an area of the pedestrian's body as possible in order to cause minimum possible injury to them. The same is true for the Hexa or Crysta or Baleno or any other car in our market for that matter.

Personally, I feel that bull-bars look ghastly on modern vehicles apart from endangering the life of other road users, pedestrians and motorcyclists, and possibly even our own, when it messes with the deployment algorithms of the safety ECUs. The algorithms are carefully designed, as someone mentioned in a previous post, and the IMUs (inertial measurement units) have to be carefully calibrated for the design and chassis rigidity of a particular vehicle, failing which the passive safety features such as the airbags and seatbelt pretensioners may fail to deploy correctly.

Apart from the safety systems aspect, you're mechanically altering the design of the car by bolting something on to the chassis. Surely, that isn't something the manufacturer intended?

Is not getting a repairable ding or a scratch really worth endangering the lives of others on the road?

Just my humble opinion.

[Satshan]

Reading through a lot of test drive reports and T-Bhp official review, the Automatic makes a lot of sense. However, my confusion is between XMA and XTA. Yes, XTA does offer a lot more features however due to 19 inch rubber, this will affect overall mileage and cause higher replacement costs. Does XMA make more sense here and does the 16 inch rubber good enough for most driving conditions?

[IshaanIan]

Originally Posted by Satshan

however due to 19 inch rubber, this will affect overall mileage and cause higher replacement costs. Does XMA make more sense here and does the 16 inch rubber good enough for most driving conditions?

I don't know how 19inch wheels affect overall mileage in anyway infact if anything, they ought to improve mileage since the profile is lower thus more energy is conserved in the rotation of each wheel (ofcourse negligible). That said, keeping everything else out of consideration (I am not aware of the exact specs of each variant and what features they have), 16 inch wheels are always better than 19 for our Indian conditions for their better shock absorption properties and cheaper cost to replace tyres since nowadays a lot of manufacturers are manufacturing 16inch tyres locally. 19inch tyres 90% of them are imported and would cost a lot to replace.

[Kishen.padiyar]

Originally Posted by Satshan

Does XMA make more sense here and does the 16 inch rubber good enough for most driving conditions?

This would boil down to your requirements. XMA has most of the basic safety and creature comforts but as you know it is lackluster when it comes to the overall package for a car of this segment.

Coming to the tyres, theoretically the 16 inchers should have better shock/bump absorption abilities but practically I don't think the 19 inchers are lacking in this regard. All the media event cars had the 19 inchers and even the 4X4 variant which has the highest kerb weight in the Hexa line up was spotted doing lot of light off-roading (going over wooden logs etc.) with a full house on board and so far I don't think we have come across any tyre bursts or any such failure. Having said that,like many BHPians have mentioned, they are expensive when it comes to replacement but I just happened to see the cost of MRFs on their official website and it is available for 12,200/- after discount. Compare that with the cost of good 16 inchers at around 8-9K, we will be looking at an extra 10-15K for a set of 4 tyres during replacement. Considering an average tyre life of 60K kms and an annual running of 15K kms, spending that extra money once in 3-4 years is not a significant thing as you get to admire those 19 inchers all the way, every time you see them

https://www.mrftyresandservice.com/s...ors-hexa/11809

Here is the link for the cost of 235/55 R19 MRFs for the XTs and XTAs.

[rkg]

Hexa sold 1213 units in April, 2017 as per Autopunditz

[IshaanIan]

Originally Posted by Kishen.padiyar

Coming to the tyres, theoretically the 16 inchers should have better shock/bump absorption abilities but practically I don't think the 19 inchers are lacking in this regard. All the media event cars had the 19 inchers and even the 4X4 variant which has the highest kerb weight in the Hexa line up was spotted doing lot of light off-roading (going over wooden logs etc.) with a full house on board and so far I don't think we have come across any tyre bursts or any such failure.

Theoretically your argument may make sense but I feel it is practically flawed No point looking at brand new vehicles and how they perform to judge shock absorption qualities. Obviously Tata is not going to fit the vehicle with such huge wheels and low profile tyres that it can't perform properly at media events. No one is saying its outright capability is marred in 19inchers. BUT over the course of time, I would like to see how often small suspension linkages like lower arm ends etc. are needed to be replaced on cars with 19inch wheels vs cars with 16inch ones. You will be surprised how much more suspension related maintenance a car running 19inch wheels will incur over time in comparison to the same car in 16inch shoes being run in the same conditions.

Originally Posted by Kishen.padiyar

Having said that,like many BHPians have mentioned, they are expensive when it comes to replacement but I just happened to see the cost of MRFs on their official website and it is available for 12,200/- after discount. Compare that with the cost of good 16 inchers at around 8-9K, we will be looking at an extra 10-15K for a set of 4 tyres during replacement. Considering an average tyre life of 60K kms and an annual running of 15K kms, spending that extra money once in 3-4 years is not a significant thing as you get to admire those 19 inchers all the way, every time you see them

Yes if you plan on sticking to MRF tyres that have come stock with the car then yes the cost difference is not so much in replacing tyres, but what if you want better tyres? That's when cost differences shoot through the roof.

[su_spatil]

Originally Posted by rkg

Hexa sold 1213 units in April, 2017 as per Autopunditz

As per last month's statistics on autoportal (https://autoportal.com/newcars/tata/...es-statistics/), sales figures for Hexa, XUV500, Innova Crysta, Skoda Yeti & Hyundai Tucson for March 2017 were 940, 2663, 7252, 1 & 146 respectively. The figures for this month, as per Autopunditz are 1213, 1999, 6589, 0 & 121 respectively. Hexa is the only vehicle with a substantial increase in numbers. All the others have sold considerably lesser numbers. It shows that quite a few footfalls are converting to sales. Off topic - the Tigor too has sold 3638 units in the first month. If Tata can convince the public that their ASS has improved, surely these numbers can improve.

[Kishen.padiyar]

Originally Posted by su_spatil

Hexa is the only vehicle with a substantial increase in numbers.

Agreed. But still dismal numbers I would say. I remember reading that Hexa had gathered around 5000 bookings at the time of launch and for the last 4 months they have dispatched less than that.

Tata badly needs to sort out the long-ish waiting time for automatic variants and also introduce a better equipped mid variant in the form of XM(O) or something to push sales or else they'd be looking at another dud from their stable.

Originally Posted by IshaanIan

BUT over the course of time, I would like to see how often small suspension linkages like lower arm ends etc. are needed to be replaced on cars with 19inch wheels vs cars with 16inch ones.

I think we know and have seen Hexa test mules being put to test for a long time even after the product was ready to launch. Tata have even claimed 8L kms of testing under various conditions and I think that is sufficient enough to say the 19 inchers are proven.

Recently our fellow BHPian VKumar had also shared his experience with a nedia car with over 17K on the odo not suffering a tyre failure despite being low profile and having a puncture.

Last but not the least, I think Pratap Bose's team sitting in the UK definitely know a thing or two about tyres and suspension

but what if you want better tyres?

It is quite obvious that all good things (read: upgrades) come at a cost and cannot be used to calculate the upkeep costs of a car.

[IshaanIan]

Originally Posted by Kishen.padiyar

I think we know and have seen Hexa test mules being put to test for a long time even after the product was ready to launch. Tata have even claimed 8L kms of testing under various conditions and I think that is sufficient enough to say the 19 inchers are proven.

Recently our fellow BHPian VKumar had also shared his experience with a nedia car with over 17K on the odo not suffering a tyre failure despite being low profile and having a puncture.

Last but not the least, I think Pratap Bose's team sitting in the UK definitely know a thing or two about tyres and suspension

Look no one is saying it is a poorly engineered product or anything like that. Suspension related maintenance is related to regular wear and tear, nothing wrong with the engineering of a car. From personal experience a car with lower profile tyres is bound to incur more suspension related maintenance over the course of time. Nothing terribly bad but it's a simple fact and a given with any car. No one is saying Pratap Bose is incapable or anything like that but don't be so naive as to think that the engineers have worked their way around simple physics buddy

PS: 55 profile tyre slowly deflating due to a nail plugging the tyre while it is travelling at 80kph and not blowing out is definitely something one should be grateful for, but nothing earth shattering in terms of the odds it overcame. I have put my 13 year old Wagon R with 14 year old Baleno Alloy wheels through more duress and come out the other side unscathed. I am not going to claim that it is the engineering prowess that went into this ancient breadbox that saved me. It is simple probability and physics.

No one is berating the car or the engineering that went behind it mate, simply saying it is also affected by the realities of life. Anyway if you want to be wowed by the testing and names behind the engineering of the car so much so that you are willing to believe it isn't affected by certain realities, no one is here to stop you from believing that.

[nkrishnap]

Originally Posted by IshaanIan

Look no one is saying it is a poorly engineered product or anything like that. Suspension related maintenance is related to regular wear and tear, nothing wrong with the engineering of a car. From personal experience a car with lower profile tyres is bound to incur more suspension related maintenance over the course of time. Nothing terribly bad but it's a simple fact and a given with any car. No one is saying Pratap Bose is incapable or anything like that but don't be so naive as to think that the engineers have worked their way around simple physics buddy

Agree to the fact that the lower profile tyres would make the suspension work a bit harder causing additional wear. But the key point is how much additional wear will it have to make it a deal breaker. In my opinion this additional wear may be very negligible to even worried about. Considering how heavy the Hexa is, they have would have surely considered this aspect and hit a balance. Only time can tell how much earlier the XT variants need suspension work compared to the ones with the 16 inch wheels.

[IshaanIan]

Originally Posted by nkrishnap

Agree to the fact that the lower profile tyres would make the suspension work a bit harder causing additional wear.

Glad to see someone who isn't blind to the realities of simple physics

Originally Posted by nkrishnap

But the key point is how much additional wear will it have to make it a deal breaker. In my opinion this additional wear may be very negligible to even worried about. Considering how heavy the Hexa is, they have would have surely considered this aspect and hit a balance. Only time can tell how much earlier the XT variants need suspension work compared to the ones with the 16 inch wheels.

Definitely that remains to be seen surely no one expects suspension related maintenance to be out of the ordinary but OEMs don't usually equip cars with suspension that is beefy enough to not be affected by a 35mm dip in sidewall height. It will definitely be interesting to see how much of a difference it makes

I feel the Hexa appeals to two types of SUV/MUV buyers; one that is attracted to the flashiness of the whole affair (I call them RR Evoque customers) and the other that is more interested in the practicalities of an SUV over a sedan apart from road presence, ground clearance and ingress/egress. I fall into the latter category.

Looking forward to some more detailed ownership reviews. Until such data comes forth, I would still be wary as an SUV/MUV buyer in India, and wouldn't be in a hurry to drool over how stunning 19inchers are in comparison to the 16s and throw all caution into the wind just as yet. In a country where roads are as bad as they are, consumer courts are as ineffective as they are and even the best brands can make you resent some of their service centers, I feel it is necessary to practice such caution, and I am sure you would agree too.