[koushik]

Tata Sumo Gold with CR4 engine is offered with tyre size 215/75R15 where as Sumo Gold with TCIC engine is offered with tyre 185/85R16. During my test drive of Sumo Gold (CR4 engine) I found it with excellent pick up power and pleasing engine sound . However it was scary to drive at 140 kmph. May I know if the replacement of tyre with 235/70R16 (used in safari) could improve stability or in general drivability at high speed.

[Nikhilb2008]

A broader tyre generally aids the handling. However, you better stick to 15". Go for 235/75-15 if you can .

[GTO]

Originally Posted by koushik

Tata Sumo Gold with CR4 engine is offered with tyre size 215/75R15

Considering it has only 84 BHP on tap and is a heavy-weight, the 215 width is more than sufficient. Of course, if you still want to upgrade, choose the size recommended by Nikhil above.

Personally, I'd stick to the stock size and upgrade to a better tyre / brand (if its delivered with the usual, lousy OEM quality tyre)

However it was scary to drive at 140 kmph

It's a 20+ year old platform that hasn't been designed for high speed driving. I would suggest capping your speed at a more conservative level (80 - 100 kph) with such a utility vehicle. Anything over is just asking for trouble.

[mayankjha1806]

Originally Posted by koushik

However it was scary to drive at 140 kmph. May I know if the replacement of tyre with 235/70R16 (used in safari) could improve stability or in general drivability at high speed.

Driving Sumo at that speed is going to be scary not only to you (sitting inside) but for folks outside as well. I have seen many Sumo driven flat out and one look at it and i would want to stay away as far as possible (Either ahead or behind).

Any tyre on Sumo will not aid that speed.

[koushik]

Originally Posted by GTO

Considering it has only 84 BHP on tap and is a heavy-weight, the 215 width is more than sufficient. Of course, if you still want to upgrade, choose the size recommended by Nikhil above.

Personally, I'd stick to the stock size and upgrade to a better tyre / brand (if its delivered with the usual, lousy OEM quality tyre)



It's a 20+ year old platform that hasn't been designed for high speed driving. I would suggest capping your speed at a more conservative level (80 - 100 kph) with such a utility vehicle. Anything over is just asking for trouble.

Yes GTO I do agree that speed around 100 kmph is appropriate for such a heavy duty car and now I do not think that upgrading tyre would make any sense.
When I learnt that Sumo design is based on Mercedes G class SUV like 461 and after that when I studied the technical specifications of Mercedes-Benz 290 GD Turbodiesel with short wheel base , which revealed identical platform like sumo with wheel base of 2400 mm , front and rear track of 142.5 cms , width 1700 mm and yet capable of maximum speed of 180 kmph I thought Gold should also run at high speed. Also the Sumo Gold speedometer is scaled for speed of 180 kmph.
Second reason for such expectation was that Safari with 3.0 L also shares the similar engine , gear box and final drive ratio and still have high speed cruising ability.

Originally Posted by Nikhilb2008

A broader tyre generally aids the handling. However, you better stick to 15". Go for 235/75-15 if you can .

OK but do you think changing to 16" from 15" can adversly affect handaling characteristic?

Note from the Team-BHP Support Team : Please use "Multi Quote" option for quoting Multiple posts, instead of creating another back-to-back post.

[GTO]

Originally Posted by koushik

When I learnt that Sumo design is based on Mercedes G class SUV like 461 and after that when I studied the technical specifications of Mercedes-Benz 290 GD Turbodiesel with short wheel base , which revealed identical platform like sumo with wheel base of 2400 mm , front and rear track of 142.5 cms , width 1700 mm and yet capable of maximum speed of 180 kmph I thought Gold should also run at high speed.

The Sumo might be *inspired* by the G Class, but other than similarity in design & proportion, there is nothing similar in their capability

[silverado]

Originally Posted by koushik

However it was scary to drive at 140 kmph. May I know if the replacement of tyre with 235/70R16 (used in safari) could improve stability or in general drivability at high speed.

I have not driven a SUMO yet, but have been a passenger in it many times, having experinced high speed runs on palm beach road mumbai in various variants.I even survived a skid @ 40kph during rains and luckily it did not sway much and driver was able to regain control.

Sumo Victa felt the most stable since it had 215 tyres ( Correct me if i am wrong ).

Anything above 100, with its softly sprung suspension and high centre of gravity and the worst factor in stability - Narrow wheelbase, you are on edge as a passenger.

I am sure we all know, Sumo's has same wheelbase as a INDICA which is why it looks like a monument from some angles.

The last seat is the scariest since you sit high and feel the body roll.It does not inspire confidence if you are on a highway run and want to drop wheels on road shoulder at high speed during a overtake.

How much does front Dip while braking?

[koushik]

Originally Posted by silverado

I have not driven a SUMO yet, but have been a passenger in it many times, having experinced high speed runs on palm beach road mumbai in various variants.I even survived a skid @ 40kph during rains and luckily it did not sway much and driver was able to regain control.

Sumo Victa felt the most stable since it had 215 tyres ( Correct me if i am wrong ).

Anything above 100, with its softly sprung suspension and high centre of gravity and the worst factor in stability - Narrow wheelbase, you are on edge as a passenger.

I am sure we all know, Sumo's has same wheelbase as a INDICA which is why it looks like a monument from some angles.

The last seat is the scariest since you sit high and feel the body roll.It does not inspire confidence if you are on a highway run and want to drop wheels on road shoulder at high speed during a overtake.

How much does front Dip while braking?

I think the centre of gravity of Sumo Gold has been lowered. With similar wheelbases (even more shorter) , tracks , height , suspension etc. and with similar diesel engine ,the Toyota Landcruiser 70 J series can cruise at 160 kmph and Mercedes Bens G 463 can cruise at 175 kmph. But the major difference between Sumo gold and the Mercedes Benz G463 is difference in kerb weight.Sumo Gold kerb weigt is 1820 kg where as the other has kerb eight of 2400 kg.
So I think that more weight can offer better stability in high speed cruising. I suggest you to take test drive and I am sure you will feel that upto 120 kmph it is a perfect car.

[nitrous]

Having owned a Sumo for 14 years, I'd recommend you stick to 215.
But, do get the best tyres in this size. Something from Michelin or Continental?

[condor]

Originally Posted by silverado

Sumo Victa felt the most stable since it had 215 tyres ( Correct me if i am wrong ).

How much does front Dip while braking?

1. Victa has 215/75 R 15.
Regular Sumo has 185 R-16.


Victa does not dip much when you apply the brake - not as much as the early Sumo's.

Originally Posted by nitrous

But, do get the best tyres in this size. Something from Michelin or Continental?

Wont Michelin be on the softer side ?

Was talking to Nikhil for my tyres, and three names came up - Yoko Geolandar, Apollo (Hawk ?), MRF Wanderer as the options for replacing my OE/stock Bridgestone Duellers.

One advantage of the MRF wanderer's is - footprint is actually as wide as a 235's.

Apollo Hawkz:

Apollo Hawkz on Vimeo

So what do you guys suggest ?

[nitrous]

There's always been very limited tyre options for the Sumo, inspite of its massive sales figures.

Anyways, Geolandar H/T or A/T?
I'd suggest choosing Yokos if the price difference isn't much.

[condor]

Originally Posted by nitrous

Anyways, Geolandar H/T or A/T?
I'd suggest choosing Yokos if the price difference isn't much.

Will I be correct in saying A/T will be a little better built, but H/T will have lesser road noise ?
Would prefer A/T - if it is better for our roads.

[nitrous]

I just checked out the Yokohama site. Looks like A/T is the only option.
Get it.

[koushik]

Originally Posted by nitrous

Having owned a Sumo for 14 years, I'd recommend you stick to 215.
But, do get the best tyres in this size. Something from Michelin or Continental?

Yes I should stick to the original tyre 215/75R15 .Change in tyre size can also change theoratical top speed of the vehicle. For example Sumo Gold CR4 with tyre 215/75R15 ,final drive ratio 3.36 , top gear ratio 0.82 will give theoratical top speed 143.5 kmph at 3000 rpm.If the tyre is replaced by 235/70R16 the theoratical top speed will be increased to 150 kmph !

When studied theoratical speed data of several cars I have observed that actual top speed is always higher by 10 to 20 kms/hr. Is that because of increase in rpm above the indicated one ?