The Maruti Suzuki Grand Vitara AT will prove to be more efficient, but the gap will not be all that large. Sure, the mild hybrid setup does help, assisting the engine and reducing load. But the bigger benefits come when the engine stop/start is also used. Engine stop/start automatically switches the engine off at long halts and restarts it when you are ready to move, in the interest of saving fuel. 

Trouble is, the AC compressor also goes off with the engine, so on a hot day, you'd rather leave the feature turned off. Do note, engine stop/start is a feature you'd find on the Hyundai Creta IVT too. 

The Grand Vitara should be more reasonable in terms of maintenance and service costs, though. 

Strictly speaking, on product attributes, the Creta IVT is a superior package. It's got a smoother gearbox, better performance and is also roomier than the Grand Vitara. The Creta IVT in base EX(O) trim is pricier than the base Grand Vitara AT Delta, but would still be our pick if you don't mind the stretch.  

 

The choice really comes down to what you are looking for from your car, and without knowing that its hard to pinpoint one. If you drive mainly in the city, we would rule out the Harrier. It is quite large, and though the steering on the petrol is light, on the whole, the car does not really feel nimble on its feet. 

It is best for highways and longer drives. Between the Tata Sierra and the Hyundai Creta, the Sierra has the advantage of newness and novelty value. You will also get more equipment, like a three-screen setup, a better-sounding audio system and a powered tailgate. However, you will have to pay more than Creta. Thus, if your budget is strict, then the Hyundai Creta will prove to be a very good all-rounder. 

Both the Kia Seltos and Hyundai Creta are mechanically identical, so you can pick either one without any hesitation. That being said, Kia recently launched the new-gen Seltos, which has a more spacious cabin, more features and a comfier rear seat than the Creta. 

Both SUVs are powered by the punchy 160hp, 1.5-litre turbo-petrol engine that's paired with a 7-speed dual-clutch automatic gearbox. 

Alternatively, if you love driving, the Volkswagen Taigun and Skoda Kushaq might be worth considering. Both these SUVs come with a 150hp, 1.5-litre turbo-petrol with a 7-speed DCT gearbox and offer better handling than the Kia and Hyundai cars.  

Of the options on your shortlist, the Hyundai Creta IVT is the best. Hyundai's CVT (IVT as they market it) is excellent, delivering a smooth experience, especially in city driving. It's free from the rubberband effect (rapid rise in engine revs without a corresponding rise in road speed) that CVTs are notorious for. Also, it works well in sync with the engine and adapts well to your driving style. 

Do note that, given that you want to keep the car for over 10 years, the Hyundai Creta that's towards the end of its life might not make the ideal choice. The new-gen Creta is about a year away, meaning opting for a current-gen car will have you miss the advancements made to all aspects of the model. 

We suggest you consider the new Kia Seltos IVT, which shares its engine and gearbox with the Creta IVT. By virtue of being built on a new-gen platform and being larger in size, the Seltos IVT makes for a more wholesome package for similar money.