Many drivers are unsure whether they should use synthetic oil in their new cars. Synthetic oil has a number of pluses over regular oil: it can maintain integrity in heat; lubricates better; has fairly good purity; and rarely ever becomes sludge, even after abuse. Most drivers will see the obvious benefits synthetic oil has to offer and decide to use it in their car. However, even with the synthetic oil's numerous benefits, the real difference is made in how you care for your car.
First of all, consider how regular you are with changing your oil. You car's oil needs to be replaced every 3 to 5K miles, before it breaks down and potentially damages your engine. Synthetic oil is a great option for drivers who tend to forget or delay oil changes, since it is breakdown resistant, even after extended use. Drivers who dutifully change their oil on schedule, however, will probably never get any benefits from synthetic oil's longer lifespan because it'll never be used long enough to make a difference.
Synthetic oil can last a long time without deteriorating. If you're changing your car oil based on mileage, then switching to synthetic could save you money. Regular oil needs to be replaced after 6 months or after 5K miles. If you drive less than that distance in 6 months, then you're not getting the full mileage out of your oil. Switching to synthetic oil which lasts for a longer amount of money will help you get the most out of each oil change. You might save money by having to change your oil less frequently, and you'll definitely save time.
Synthetic oil can withstand heat better than regular, which is one of the most common reasons people have for switching to synthetic. Regular oil starts to break down as the temperature increases, and continues to deteriorate as it gets hotter. If you regularly put your engine into situations where it will be in high heat, synthetic will help protect your engine against damage. Idling your engine for long periods of time and driving in high temperatures or altitudes will overheat your engine. Hot climates and thin mountain air won't cool your vehicle's engine very well, so people living in these climates should definitely consider synthetic oil. High performance vehicles will also benefit from synthetic oil.
There are a lot of entities that recommend using synthetic oil, even to people who don't need it. For example, synthetic is recommended for anyone that drives in stop-and-go traffic. But since all of us drive in stop-and-go at some point, that's a bad recommendation. You should only use synthetic if you're driving in stop and go traffic long enough that your engine's cooling fan turns on, and only if you're doing so daily. Also, if you only drive short trips, people may recommend synthetic oil as a way to protect your engine. However, short trips, regardless of your choice of oil, can damage your motor. No matter whether you use synthetic or regular oil, your engine was designed run for at least 20 minutes. Running synthetic in these situations might be better, but tests have shown that the benefit is minor.
If you've decided synthetic oil is right for you, use caution when buying synthetic oil. Many places try to sell synthetic "blends" as a cost-saving measure, but the contents of this mixture aren't always the same. You could be getting regular oil with a little bit of synthetic thrown in for a higher price. The best thing to do is to buy either pure synthetic oil or not bother with it at all. The exception to this is if the blend you're buying is coming from and made by your vehicle manufacturer.
Last but not least, what do auto manufacturers have to say about synthetics? Most state that "any oil that meets API standard specifications can be used in your vehicle." That means normal oil is just fine. For most people, new cars will operate for a very long time without the benefit of synthetic oil so long as they are properly maintained and used normally.