You need a new car or a used car. Whether it's your first car, or you're a seasoned buyer, its always good to take some expert advice. Carwale’s buying and selling advice does just this, offering useful tips for everything, from your legal standing to explaining the new number plate system.

Before you go any further you need to consider one thing. Is the car you're looking to buy suitable for your needs? It may sound like a simple question - but it is so easy to be distracted by flash or impractical cars when you're looking for a new car.

Prioritise what you really need in a car. Is it space or speed? Looks or practicality? There's no point buying a roadster if you want to carry your family of 4. Likewise, why buy a big clumsy off-roader if you're a city dweller? Why considering mileage at top-priority while you don't travel even 10 kms a day? A petrol car or diesel car?

To answer these questions, and make your buying and selling experience as easy as possible - read on - we've compiled the guide that should provide the answers to all your questions.

New or Used

• New is New! Nothing beats the smell of a new car, the thrill of driving away in a car that is yours, one that's never been owned by anyone else, but it comes at a price in the form of depreciation. You can virtually write off 20 per cent of the purchase price the moment you drive away from the dealer because it's then a used car. Cars depreciate faster in the first two or three years of their life and the new car buyer has to cop that for the pleasure of being the first owner. By buying used it's possible to avoid the heaviest depreciation. Cars will still depreciate in their latter years, but at a lower rate. New car buyers can choose the colour of their car, the trim colour, the engine, transmission and other options and accessories, but used car buyers have to take what's available.
• New car buyers have the reassuring backup of a new car warranty so they know that if anything goes wrong they won't be up for a big repair bill. Anyone buying from a used care dealer will also have a warranty, but it won't be for as long as the new car warranty. Private buyers don't have any warranty.
• By buying used it's possible to get behind the wheel of a better car than you might when buying new. For the cost of a new Zen or Indica it is possible to drive a used City or Scorpio.
• There is always the risk of buying a 'lemon' when buying used because there is no way of knowing how previous owners have treated a car.

Petrol or Diesel

Both petrol and diesel engines have their own advantages and disadvantages. One is good at one thing then bad at other and vice versa. The gaps between the two are narrowing day by day so you can choose either ot them on the basis of your needs.

Diesel engines used to be slow and noisy, but the latest diesel engines are as refined as petrol ones. Now diesel engines are fitted in a number of high-performance models also. Diesel engines use 'Turbo Charged', 'common-rail' and 'direct-injection' technologies, with the very latest and most advanced having super-precise "piezo-electric" injection. Diesel engines emit less carbon dioxide, so they are better in terms of pollution. However, diesel engines tend to pump out more and larger waste hydrocarbons called particulates, which are associated with smog formation, respiratory and cardio-vascular illness. Increasingly, diesel engines are being fitted with particulate filters, but this is by no means widespread at the moment.

Petrol engines are getting cleaner and more economical, too. Direct-injection technology now features in a number of models. Performance-minded drivers still tend to opt for petrol rather than diesel cars, though many diesels can accelerate between 50-80kmph faster than petrol equivalents - a more useful advantage than a quick
0-60 standing start time in everyday driving.

The prices of new diesel cars are usually slightly higher than for similarly-specified petrol models, but they have better resale value.

Diesel is nearly three-fourth in price as compared to petrol and is therefore easy on the pocket. They also give substantially more mileage as compared to the petrol version. As for your planning to purchase a car in the near future, bear in mind that a diesel car makes sense financially only if your annual mileage is more than 13,000-15,000 Kms. If you feel that your annual mileage will be less than that, close your eyes and opt for a petrolversion. Always remember this simple rule that if your driving is less than 12,000 Kms annually never think diesel.

Now, if you have made up your mind to buy new or used car, we strongly recommend you to read carwale.com's new car buying tips and used car buying tips before making any further decision.