Of late, the concept of engine downsizing is increasingly becoming the keyword in the automotive industry. We see several manufacturers preferring this method to gain profit at a reduced cost of investment. But what does engine downsizing actually mean? In essence it is about getting the performance of a bigger from its smaller counterpart. Let’s say a 2.0 litre engine pumps out 140bhp of power and 200Nm of torque and it has a certain level of emissions. Getting the same performance figures from a smaller engine for instance 1.2 litre or 1.4litre while reducing emissions, is the idea of downsizing. There are several ways to downsize an engine with the most common one being forced induction. Forced induction either by turbocharging or supercharging helps achieve immense increase in performance and at the same time reduces emissions and fuel consumption manifold. Forced induction of smaller engines has brought them on par with their bigger counterparts. Nissan GT-R, Porsche 911 GT-2 have the same sort of performance figures with the likes of Ferrari and Lamborghini. With Formula one adopting to turbocharging in 2013, we can expect some interesting challenges rising within teams and mimicking on the road cars as well. Other less familiar strategies include tuning the intake and exhaust geometry and optimizing the valve timing for a wide rev range like Honda’s Variable Timing Electronic Control [VTEC], Toyota’s Variable Valve Timing –Intelligence [VVT-i], BMW’s Valvetronic and so forth.
Given these facts, engine downsizing now strongly raises the question regarding the future of the Naturally Aspirated powerplants.
It may be hard to see in India but here in the US the whole car industry is going crazy with "downsize and boost" for petrol engines. Basically they're using smaller petrol engines with turbochargers. Most of the new engines also have direct injection and variable valve timing.
Different companies are taking different approaches. So far the four with the most visible turbo direct injection engines are Ford, GM, Hyundai, and BMW. They've all taken different approaches.
BMW has the largest number of these engines, but their design philospophy is different. As a company that only builds high end products, BMW can just overengineer everything and doesn't have to optimize for cost as much as the others. The other three take a very long time to design an engine, but their engines cost much less.
Ford started out with a big 3.5L V6 turbo direct injection engine intended to replace V8 engines in trucks. They now have the most fuel efficient full sized petrol pickup truck in the US. Ford also has plans for a whole series of smaller engines.
Hyundai started in the middle with a new engine for the Sonata. It's their top selling model in the US, and the new engine is something like a 2.0L I4 with 200+hp. It scored a 35 mile/gallon (14.7 kmpl) rating on the US govenment FE tests, which are really quite accurate for cruising at a steady 110-120 kmph on an major highway or driving on 2 lane roads (more speeding up and slowing down) at 100 or so.
GM started smaller with a 1.4L 136hp engine for the Cruze. The Cruze with this engine is estimated to get about 17 kmpl on highways as per the US government tests.
Many of these engines probably won't make it to India any time soon. They cost more than normal petrol engines, raising the price of the car too close to that of a diesel. They're really best suited to petrol crazy markets like the US and Japan. In Europe and India people are much more accepting of diesels, so these technologies that make a petrol engine more like a diesel will be slower to catch on. The most likely ones to make it to India are the ones that go into luxury cars like BMWs. Other than that, the next most likely would be a 1.2L engine installed in a hatch. Turbo direct injection petrol engines can make a lot of power relative to their displacement, so assuming Indian tax law treats one of these engiens the same as a naturally aspirated petrol engine some company might be able to offer a hatch with well over 100hp while retaining the lower excise tax rate. If it's done right it may not even reduce FE, at least not significantly. Ford uses both naturally aspirated and turbo direct injection 3.5L V6s in the Ford Taurus, and the turbo motor gets the same FE despite producing an extra 100hp (about 260 v. 365).
Basic philosophy is to reduce Carbon emission per mile. In layman's language, it translates to increase or better FE. Over years, companies got drivers addicted to powerful engine and quick acceleration. Now they have to produce more power with smaller engine. AFAIK, Hyundai is a mass car producing company which dropped 6 cylinder engine in favour of 2.0L turbo charge engine (as mentioned by Mike) in their popular USA model, Sonata, to compete with 6 cylinder engine equipped cars of Honda Accord and Toyota Camry. etc., in this segment, apart from the most powerful 2.4L and fuel efficient non-turbo (conventional) engine. However, new technology does not come free. There is a cost associate with research and production of these engine. Hyundai is working on a 1.2 L turbo engine for i20 (which is also sold in India) to replace 1.4L engine. In India, reduction in excise duty by 1,2L turbo will cover the increased cost and car will have better acceleration and FE than present i20 with 1.4L engine.
Disclaimer: I don't own or drive either a Maruti or Suzuki or Hyundia or plan to buy same in near future.
I greatly appreciate your opinions. Thanks for sharing.
Will the much sought after Bimmer's downsized 2.0litre turbo make its foray into India as well? With about sort of 250hp and 300 Nm this four pot banger should give other luxury car manufacturers a good run for their money. I haven't heard of Hyundai's 1.2litre turbo. Can Safe_driver elaborate this?
Road cars apart, what's intriguing me is the turbo tech in F1 in 2013. Massive reduction in displacement from 2.4litres to 1.6litres is a challenging task for the teams on the grounds of performance. However, the high revving turbos are expected to enhance the spectacle of what is considered the pinnacle of motor racing.
How does the excise duty work regards to engine displacement? All I know is that the manufacturers get a waiver if the length of the vehicle is less than 4m.
@Harinarayanan - what they're basically trying to do in essence is improve the power-to-weight ratio of the engines. For a given state-of-art the max. power that can be extracted from an engine without forced induction is dependent on the various parts (especially their weights vis-a-vis strength). Once the lower weight limit is reached forced induction is used to further enhance the P-W ratio - for this a slight increase in weight (for adequate strength) apart from the weight of the forced induction mechanism is acceptable.
For excise, the engine capacity is (traditionally) the benchmark since this is the only thing about an engine that's physically fixed - power/torque etc are design dependent. And also the physical size of the car (which is again something that can be measured with a foot-ruler!). Though things are now changing - in the west excise is dependent not on these things or only partially on these things: Emission is the benchmark which basically means cheaper cost-to-customer if better emissions and hence more sales for the manufacturer.
@Rohit - What's the benchmark as to engines for the cars to get the excise duty benefits?
I don't know the excise rate but in India the excise is based on the engine capacity in following slabs:
Ah, 800cc benchmark is kinda challenging to the manufacturers and only a few hatches slot in this tight slab. I did not know this. Thanks for the info.
By the way, Mike, how "small" is the US small engine on an average?
However, I totally understand their desire to eke out even more power from the practically limited size of engines!