Ask a Technician: The Most Common Car Questions
1. My owner’s manual says that regular unleaded is fine for my vehicle. Would it be better for my car if I splurged on premium gas or is that an unnecessary waste of money?
Save your money. If your owner’s manual recommends regular unleaded, then that’s perfectly fine. You’re just wasting precious pennies if you pay for a higher octane fuel. Most of today’s cars, with the exception of high-performance engines, are tuned to run on regular unleaded fuel with little advantage to be gained by using premium. Here’s the skinny:
Your engine’s cylinders hold a mixture of gas and air. The cylinder compresses that mixture very quickly and your spark plug ignites it. That little explosion (like a cannon firing) is the combustion in an “internal combustion engine” and creates the energy your car needs to move. The octane of a gasoline tells you how much compression it can stand before it ignites spontaneously—the higher the octane, the higher the compression it can take.
Most cars have an 8:1 compression ratio, which is perfect for regular unleaded gas. That means the cylinder is compressing the gas/air mixture at just the right rate.
If the gas isn’t a high-enough grade for the compression rate of the cylinder, it’ll ignite early, before the spark from the spark plug. And that’s bad for your engine. Those early explosions result in knocking and pinging. So, if you don’t hear any knocking and pinging, you’re using the right grade of gas. If you do hear those sounds, try upgrading to a premium gas. But, for most cars, using a premium gas doesn’t give you or your engine any advantage.
2. Is my mechanic secretly laughing at me when I try to make the noise my car is making to explain the problem or is that helpful information?
Not if they're a serious mechanic. Those nutty sounds you’re making can provide really helpful information. But it’s better to try to describe the sound. Was it high-pitched? Did it sound like metal scraping? Was it more of a thumping sound? As Mom used to say, use your words.
- High-pitched, metallic screeching sounds can be a warning that your brake pads are worn down.
- Whining can be a sign that your transmission, differential, (or children) need help.
- A low rumble can mean a wheel-bearing issue.
- Squealing can mean a loose belt.
Be sure to describe not just the sound itself, but where and when you hear it. Does it happen when you shift, turn, go uphill, or when it’s cold? All of those details can be a great help in diagnosing the problem.
Better yet, see if your mechanic will go for a ride-along. If they’re willing to go for a short drive with you, you'll be able to show them exactly when it happens and what it sounds like.
3. How can I tell if my car really needs the work my mechanic says it does or if I am being ripped off?
Whether you’re just taking your car in to track down a weird sound, or you've had to take off work and rearrange your schedule to make time for repairs, nobody enjoys being without their vehicle. No matter the reason, you’re at the mercy of the mechanic, and unless you’re a closet grease monkey, you don’t know what’s wrong with your car. Worst of all, you don’t know whether your mechanic is being straight with you.
Here's how to keep from being swindled:
- Look for credentials. Make sure your mechanic has the proper accreditation. Certificates are usually posted in the office area. Make sure they’re the real deal.
- Are they going to charge you for the diagnosis? Most good mechanics won’t nickel-and-dime you with charges before work even begins.
- Will they give you a written estimate? An itemized invoice?
- Ask them what they’d do if it were their car.
- Educate yourself about cars. Knowing what to ask and what to listen for in their answers is gold.
If you don’t like what you hear—and you can afford the time and the effort involved—you can always get a second opinion.
Do your homework and find a mechanic you trust, and then you won’t have to worry about being ripped off. At Germain Toyota of Columbus, we pride ourselves on our trustworthiness, so don't hesitate to ask questions.
4. How can I find a trustworthy mechanic?
Going to the mechanic is like going to the doctor: trust is everything. Start by asking your friends and family for recommendations. Word of mouth is a great way to get started in your search. Find people who have the same make of car and find out who they go to and what they think of them.
Try one out. Take your car in for something small like an oil change and see how they treat you. Was the place clean? Was the service friendly? Go for a coffee date before you commit to a relationship.
Look around the shop for accreditation certificates. Things like Auto Service Excellence (ASE) are a good sign. If you belong to AAA, see who they recommend in your area.
Start your search when you don’t need to take your car in for repairs. If you wait until your car’s in a bad way, you’re likely to rush to judgment just to get your car worked on. By someone. (Anyone.) So take the pressure off and find a good mechanic when you don’t need one.
And don’t forget to check out our service department. No one knows your car better than we do.
5. What are the advantages of taking my car back to the dealership where I bought it for service?
There are some serious advantages to taking your car back to your dealer for service. It might cost a little more, but, as they say, you get what you pay for. Here are just a few reasons why your dealer might be your best choice:
- Expertise. No one knows your car like a dealer technician. Dealer technicians (and the rest of the staff too), usually undergo extensive continuing education to keep them up to date on the latest techniques and vehicle enhancements. Also, dealers tend to pay their mechanics well and expect a level of excellence in return.
- Specialization. Your dealer’s mechanics specialize in your car. The world of auto repair isn’t a one-size-fits-all world. Knowing the ins and outs of your particular model is a big advantage offered by most dealers.
- Depth. At your dealership, there will be multiple levels of knowledgeable people from technicians to supervisors and managers who oversee the quality of the work. You can always escalate an issue if you need to.
- Convenience. Many dealers offer shuttle services or loaner cars for you to use while your car is being worked on. And, often, their waiting rooms are places you’re actually willing to sit down in.
- Warranties. If your car is still under warranty, your dealer will repair your vehicle for free. Most dealers also offer nationwide manufacturer-backed guarantees for the work they do. That means, if you’re out of town and have a problem, you can probably find an in-network repair shop to handle the repair for free.
- Recalls. Dealers are also the first to know if there’s a part recall and you’ll have the problem taken care of quickly and painlessly.
- The Big Cheese. The dealer you bought your car from is answerable to their manufacturer. They need to provide quality service in order to stay in the family, so it’s in their best interest to keep you happy. A happy customer is a repeat customer. And, if you’re happy, you’ll probably tell your friends, and good word of mouth is the best advertising money can’t buy.