Porsche 993: Top 5 Car Myths

Don't believe everything you hear about cars. You've likely bought into some untrue facts that are costing you more than they should.

By William Henderson - March 17, 2015

This relates to the Porsche 993 (1993-1998).

Admit it, you're convinced that something you heard once about cars is true, even though you have no proof to back it up. You change your oil every 3,000 miles whether you need to or not, you gas up at the crack of down because you're convinced that's the best time to do it, you never roll down your windows, even on mildly temperate days, because doing so affects your fuel economy, and so on. There are as many myths about driving and cars as there are cars. Here's the skinny on five common myths and what you can -- and shouldn't -- believe.

Myth: Change your oil every 3,000 miles or else

False false false. In fact, some cars can go as many as 10,000 miles without needing an oil change. It's just not recommend that you do it. Changing your oil around 5,000 miles seems to be the best and most cost effective bet. To better gauge when it’s time to change your oil, get into the habit of checking it once a month. As long as your oil stays golden, it’s good to go. When your oil turns black, then it’s time to change it. Dirty oil won’t lubricate your engine as well as clean oil, which can cause your engine to wear and eventually fail.

Figure 1. You don't need to change your oil every 3,000 miles to keep it running well.

Myth: You get better fuel economy with the AC on than with the windows down

Maybe, but likely not true. A 2004 study that GM and SAE International conducted found that using the AC on medium uses more fuel than driving with the windows down. Consumer Reports also found that driving with the AC uses more fuel.

Figure 2. Driving with the windows down is better on your fuel economy than driving with the AC on.

Myth: Let your car idle until the engine is warm before starting to drive

False. While parts of the engine and oil need to be warm before operating at 100%, letting your engine idles actually causes your car to take longer to warm up and can increase engine wear and tear. Don’t rev the engine until the engine is warm. That’s enough to keep your car optimally performing.

Figure 3. You don't need to let your engine warm up before you start to drive.

Myth: Using premium gas is better for my car

False and even falser. Gas is gas, and using regular isn’t going to do anything but save you a few bucks when you fill up. As for running on empty, over time you’ll get an idea of how far you can go once your warning light turns on, but it’s always safest to fill up rather than test just how far you can go. Running out of gas is never fun. Another gas-related myth we can debunk – filling up in the morning when the air is cool doesn’t really give you more gas for your buck. Fill up when it’s convenient, no matter the time of day.

Figure 4. Never drive on empty, using regular gas is OK, and fill up when it's convenient.

Myth: Driving on a spare tire is OK

True, as long as you drive fewer than 50 miles. Drive on it any longer and you risk a blowout. Of course, the longer you have your spare tire – whether you use it or not – can affect its performance. If you’re riding on a spare, be sure to check its tire pressure. Low pressure can cause your tire(s) to unevenly wear, and can also affect your alignment.

Figure 5. If you have to drive on a spare, aim to go fewer than 50 miles on it.

Common Questions

Why should I drive with the AC on rather than with my windows down?

According to Consumer Reports, driving with the AC on helps you stay more alert and more comfortable than driving with the windows down.

How often should I change my oil?

Aim for around every 5,000 miles, but always change your oil when you notice that it has turned black.

How far can I drive on a spare tire?

Most owner’s manuals suggest driving no farther than 50 miles on a spare. Consider using it just long enough to get you from where you changed your tire to where you can replace it with a regular tire.

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