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-   -   Engine Capacity (cc) or Power (bhp)?? (https://www.team-bhp.com/forum/indian-car-scene/78766-engine-capacity-cc-power-bhp-3.html)

One thing about the road tax calculation in India:

Our road tax calculation is still done based on the CC !! They don't even care if it's a petrol or diesel!

IMO, the 1500 cc tax slab is just stupid idea. First of all there should be different slabs for petrol and diesel engines.

Secondly, the newer engines produce more power with less CC. So, cubic capacity alone shouldn't be the basis for that.

Mate,

Are you nuts !! (no offense) but we already are paying through our noses for cars, and the excise/taxation/customs policies are confusing enough as it is. If anything what needs to happen is that diesel price needs to be de-regulated, and, we need to standardize all taxes throughout the country (not just for cars)

cheers!
imp!

NA's are relatively cheap to manufacture, ergo, they should be cheaper to purchase. They (NA) are also cheaper to maintain. This is also tied into the way the turbo works, all the engine internals are at much higher stresses, and even though the engine block is designed to handle these, the stresses will take its toll on the engine eventually (probably long after you've sold it and moved onto a newer car)
Taking care of a turbo can be a pain, ideally, one should let the car idle for a couple of minutes on a cold start and before switching it off. This is to allow coolant (oil) to circulate through the turbo properly. Many newer cars have a "cut off switch" (forget what it is called) that will make the engine idle for a given amount of time after you've switched it off. I don't think any of the cars we have here offer them.
Before the Turbo kicks in, the car behaves like a naturally aspirated engine. i.e. if it is a 1.8L propelling a Passat, it will behave like it is a 1.8L engine. Compare this to the 2.4 propelling an Accord which is roughly the same size. This makes the car feel sluggish until the turbo kicks in. Once the turbo kicks in, the car suddenly becomes much faster. Hence the term non-linear power delivery. Think of turbo lag.

Cheers !
imp!

P.S
I don't know much, but I hope that my basics are essentially correct. Please let me know if I am wrong.

The part of your statement I highlighted is a fallacy. Strain is strain on a big capacity engine or on a small capacity engine. The number of cylinders and the cc have no influence on the wear factor. If an engine is designed to take a certain amount of stress for a set life cycle then that is it. No ifs and buts.

Also turbo technology has changed dramatically over the past 10+ years, which is why manufacturers come back to them.

One important argument, which makes small capacity engines disrable is the weight issue.

First of all the engines get more compact, which means less space is required for their housing. Less space means less weight.

The smaller engine has got less weight to start with.

This makes it easier to balance the car, which means the manufacturer doesn't need to bump up the car's weight for better balance.

The results are better handling cars, less fuel consumption and less tcomponent wear.

I told this because we had to pay extra tax for out 1570 cc TUD5 diesel engine equipped car since it is above 1500cc slab. The car just has 60 or 57 bhp power. Since it is an NA diesel, it has more cc than a petrol for the same power. So paying extra money just for that cc and not for more power didn't make any sense. A more powerful petrol engine under 1500cc can escape this tax slab!

yeah.. unlike americans we dont need things that are big in size.. i prefer pocket rockets!

There is a saying that " there is no substitute for cubic capacity". Less CC and More power is very well but when it comes to overall reliability and tolerance of the engine, cc plays a crucial role.It is true that modern petrol engines( eg: Honda engines)produce high BHP figures and great torque at HIGH RPMs.But vehicles with such engines are never meant to be haulers, but will be excellent performers. But to pump enough low end torque at low RPMs (without revving up the engine) for hauling , ie from 1400-1500 Rpms, CC is inevitable. Offcourse for fun vehicles, this rule has no application. I think a healthy mix of power and CC,which was done in the earlier Scorpio 2.6 Turbo DI chaindrive, is the best way to go.

Hi
To me the output is more important. Greater bhp is what i look at in a engine. But longhorn had made it clear. The torque factor is applicable to indian roads. I agree with his views.
Cheers

Where the engine produces max torque does not depend on the CC of the engine. If an engine is designed to produce power/torque at high rpm, it will do so, whether it is a 1ltr engine or a 5ltr engine.

The 3471cc Accord V6 produces 339nm@5000rpm but, the 1991cc Cruze engine produces 327nm@2600rpm. Thats 96% of the Accord's torque at 52% of its rpm and with an engine thats is just 57% of its size.

These days, if an engine designer needs a certain amount of torque at a given rpm, he need no go in for higher cc, he can achieve the same results with a low revving small engine and forced induction.

Shan2nu

Can somebody please help me understand this with numbers, with body/mass to power ratio prospective? Eg: Mahindra Scorpio > weight - 2.5 tones (2X4), 2.2 ltr engine and 120bhp. For the weight of this scale, I believe it should handle an easy 3L engine with a min 220bhp plus, but it’s down sized to achieve mileage! Agreed. 2.2L with 120bhp sounds to be a stress for a fully loaded Scorpio driving up the hill with 2.5 tones of its own weight, plus 600kgs of passenger weight and 300kgs of luggage (Total 3.4tones). So will more “bhp” or more "CC" helps in this scenario? Also, where does torque come into picture?

more BHP with less CC should be ideal for small cars but i guess for SUV,s as the weight of the car goes up you need more cc, i,am really not sure, request advise...

I guess with less cc & more power you are able to achieve more FE. Also it will be economical. Thats the reason we are getting such cars in India now. Mariti's 1.2 K series is classic example of that :)

In the current context Power/ torque matter more than the engine size (CC). Earlier days the two were directly proportional in most contexts.

Well, power isn't everything.
In an SUV, like the Scorpio you've mentioned, torque is the key factor.
To climb a hill with 3.4 tonnes to pull, having a torquier motor is the best option.

I think it again boils down to what the purpose is for . The mitsubushi evo series are all 2 litre engines and they produce mind numbing power and some are tuned to even a 1000bhp. So thats a standing example.