[ghodlur]

Came across a half page article in today's Economic Times (Mumbai) which mentioned as to how the car manufacturers in India are innovating increasing profit by reducing the weights of the vehicles manufactured. Leading the pack are Mahindras, Maruti Suzuli, Mercedes benz etc.

The article says Maruti benefited by 147 crores by reducing 1 gm of weight on the components. Mahindra trimmed off 60 kgs off Scorpio over last three years, new XUV is 250 kgs less than industry SUV bench mark of 2 ton.

Weight-wars: M&M to build slim SUV, Maruti for one gram weight reduction in components - The Economic Times

[harimakesh]

IF roughly Rs.300/- per kg is the cost of metal & material on the reduced weight of the SUV then 250 Kg weight reduction is straight 75K savings per SUV for the car company due to aggressive weight reduction which amounts to 6% of the XUV price

[srishiva]

I think the importance of weight reduction is towards lowering fuel consumption mainly without compromising safety. Its being done by all manufacturers.

[HammerHead]

Weight reduction, If manufacturers can achieve it without compromising safety of the vehicle and durability of the components, I see no harm in it. On other side it will help F.E.

[Aroy]

It all depends where the weight is reduced

1. Body. Modern trend is to use lighter sheets of higher strength. Further modern CAD enables increasing stiffness while reducing the weight by better geometry of sub assemblies. An example is to have a ribbed roof which reduces the weight while gaining extra stiffness and support in case the car turns turtle.

2. Engine. Use of Aluminum in both Head and Block reduces the weight lot. Changing from push rod to overhead cam reduce weight. Changing from chain drive to cogged belt reduces weight. Using high strength alloys at critical points also reduces weight. All this weight reduction also makes the engine more reliable, within normal running parameters. The problem starts if you "hot rod" the engine. It simply cannot take it, so be careful while remapping the ECU for higher power, the engine may give up!

3. Seats and Trim. Plastics are invading every where. There are plastics and there are plastics. Light weight high strength engineering plastics can result in dramatic weight reduction.

In short weight reduction, while increasing the FE, may not decrease the cost as much as we think. Die Cast Aluminum is much more expensive compared to Cast Iron, so is high strength sheet metal compared to normal mild steel sheets.

That said, assuming MUL produces 1 million cars, a reduction of 1 gram weight is reduction of 1,000,000 g or 1,000kg or 1 ton. Now what metal costs 137 crores/ton (= 13L/kg or 13,000/10g) that is nearly the price of gold.

Just the right time to sell my 600+kg Alto K10 and get at least 100 crores!

[SPIKE ARRESTOR]

With reference to XUV 500, which is a monocoque, would like to mention that M&M NGCS vehicles (ladder frame) have chassis weighing between 140-180 kgs.

Spike

[vineethvazhayil]

Is this a valid assumption to make that the lighter weights means lower production costs? The lighter materials which meet the strength requirements are more often than not more expensive than let's say automotive grade steel (carbon fiber, anyone?)..

[ukderebail]

I am only worried if the weight of the vehicle is lesser and engine is powerful, will the braking system be effective. With tubeless tyres unless one has ABS system one is bound to meet with accidents. The brakes skid uncontrollably without ABS, i hope manufacturers address this problem. After two experiences of unable to control my A Star once while it was raining my vehicle veered to the left uncontrollably when i applied brake, second time i applied brake it skidded uncontrollably to hit the railway track a distant of almost 20 feet.

[vipul_singh]

On sites like mbworld, bimmerpost / bimmerfest, germancarforums, TTAC etc., people (or at least enthusiasts) are aghast that replacement versions of cars weigh more than the previous versions. So, if Indian manufacturers are able to reduce weight, it might be a step in the right direction.

On the other hand, I am not sure (or am skeptical) that they make the engineering changes needed to ensure that the monocoque strength / body's dent resistance is not reduced.

Without specifics, it is really difficult to support or dislike this trend.

[avisidhu]

^^ well said. The title seems to suggest that it's purely from a perspective of increasing margins, which then automatically makes people suspect that something must have been compromised, even though it might be a win-win for all.
Eminent BHPians have tried to explain time and again that structural integrity and weight of metal used are not necessarily proportional, but I guess we are naturally inclined to having these perceptions, me included

[samarth.bhatia]

Hi,

I have read two separate Test Drive Reports on the XUV500.
For the front body panels being in Plastic, the reasons stated have differed in both the reviews:

1. Pedestrian Collision Safety is enhanced as the plastic panels are expected to bend and provide some reduction in the force on impact with the pedestrian.

2. Weight Reduction: This makes perfect sense as well. Dual benefits: One in the production cost, and two, a lighter vehicle would inherently consume lesser fuel thus maintaining a better FE. Of course this would be a good marketing point as well.

Most body bumpers are also made in Plastic these days for the same reasons stated above.

BTW, materials manufactured in plastic for typical Assembly Line Manufacture end up reducing the actual cost of assembly as well. So this may be looked at as the third benefit.

Also, I believe it is possible to have better contours in an easier manner with plastic as the Material of Construction. This directly benefits the manufacturer as well.

Cheers and drive safe.
Sam

[scopriobharath]

Weight Reduction is one aspect - Mileage another. It definetly reduces cost and also is a good move as metal prices are always rising.

One Major aspect is Insurance - Metal has just 20% Depreciation. But Plastics have 50% depreciation. So this translates yo if your plastic fender / bumper is damaged in the unlikely event of an accident, you will need to pay more from your pocket. The insurance company's pocket is safe. Another way of fleecing the average indian.

Project the aspect of Green - environment - weight reduction - mileage etc, so that insurance claim aspect is overlooked

[subscrive]

Originally Posted by scopriobharath

Weight Reduction is one aspect - Mileage another. It definetly reduces cost and also is a good move as metal prices are always rising.

One Major aspect is Insurance - Metal has just 20% Depreciation. But Plastics have 50% depreciation. So this translates yo if your plastic fender / bumper is damaged in the unlikely event of an accident, you will need to pay more from your pocket. The insurance company's pocket is safe. Another way of fleecing the average indian.

Project the aspect of Green - environment - weight reduction - mileage etc, so that insurance claim aspect is overlooked

My sentiments exactly. Why are plastic components not considered at par with other components?
What are the basis of this 50% figure?

[Aroy]

Originally Posted by ukderebail

I am only worried if the weight of the vehicle is lesser and engine is powerful, will the braking system be effective. With tubeless tyres unless one has ABS system one is bound to meet with accidents. The brakes skid uncontrollably without ABS, i hope manufacturers address this problem. After two experiences of unable to control my A Star once while it was raining my vehicle veered to the left uncontrollably when i applied brake, second time i applied brake it skidded uncontrollably to hit the railway track a distant of almost 20 feet.

Actually lighter vehicle will stop faster! The heavier vehicles have a lot of momentum to loose while braking. In your case your brakes need adjustment as they seem to be pulling to one side. Skidding may be due to a light coating of sand/dust on the road, else there may be some oil and no amount of ABS can help you. Next time the car starts skidding, let off the brakes a but and then apply them.

Tubeless tyres have no special affinity for ABS. Tubed or Tubeless the treads is what matters and it is similar on both types for the same design.

[Ascari]

The weight reduction is a step in the right direction.For example BMW uses lighter aluminium for the fendor,bonnet and the boot lid.They are now using high strength steel in key areas.This does not mean they have saved cost and are compromising on safety,they are infact much safer.The XUV would be much more safe than the Scorpio in a crash due to more modern tech going into it's production.

If weight of the car was a benchmark for safety of a car none of the Japanese cars would pass safety tests!