NS: Can I switch from synthetic oil to regular oil? I’ve read it’s a myth, but my mechanic says you can’t. By the way, I read your column here even after I moved to Venice, Florida.
a: Synthetic oils and regular oils, for the most part, use very similar base stocks.
Synthetic oil differs from conventional oil in the way it is refined. The molecules in synthetic oil are very similar, whereas the molecules in conventional oil differ in size. This is one reason why synthetic oil flows more quickly and stays cooler than conventional oil.
Yes, you can switch back and forth without loss, however, in my opinion, the benefits of synthetic oil outweigh the cost of a traditional oil change.
NS: I’m going to buy a car – maybe not brand new, but maybe a few years old.
I have a 2010 Toyota Camry and am very happy with it and want to get it. What are the benefits of buying from a Toyota dealer? I see some great deals from other dealerships that are not Toyota dealers.
a: When buying a used car from a new car dealer who sells the same brand of car, in many cases you are getting a “fresh” trade-in. Also, franchise car dealers will have exclusive access to factory auctions.
These recent trade-ins or manufacturer auction vehicles may have lower mileage, be one-owner vehicles, and may have a better overall history.
That doesn’t mean that other new and independent (big and small) dealers don’t have good cars. In fact, some car dealers will make major repairs to the old car – in some cases replacing the tires and battery – to give that used car the feel of a new car.
As with any used car, it is always best to have it appraised by a skilled technician before buying.
NS: Our 2013 Ford Taurus key fobs are not locking and unlocking the car doors on a regular basis. The car was a used car purchased from a dealership, and the warranty expired in 2019.
Do I need to work at a Ford dealership, or can a repair shop fix the problem? I’m not sure if the fobs, unlocking receiver or the actual car lock are the problem.
a: Many auto parts stores have a simple tool that can check to see if the key fob is transmitting, which will help verify the operation of the fob.
If the fobs are only working intermittently, a very common problem is that the battery becomes loose and loses connection. In fact, Ford designed a new gasket/shim for the fob that solved this problem.
If the fobs are transmitting, then the problem is with the receiver. Any competent repair shop will be able to diagnose and conduct repairs. I have found that a franchise dealer, or an automotive locksmith, is more familiar with these issues.
NS: I brought my Infiniti Q50 – with 50,000 miles – to my local dealer for an oil change and alignment. He recommended four other services: transmission fluid change, power steering fluid change, throttle body cleaning and differential fluid change. I decided to go with a transmission fluid change, but declined the rest, as none are listed in the service manual and they cost an additional $900.
When will the services I’ve declined be required? I have trouble going with expensive services deemed necessary by dealerships that are not in the manual.
a: All these fluid changes are only needed if the fluid has started to deteriorate. As a general rule, power steering, transmission and differential fluids last a lifetime, according to Infiniti and, although they should be checked, there is no recommended replacement.
Throttle body cleaning is the same. If the vehicle hesitates in cold weather, it may be the result of carbon buildup in the throttle body, which is corrected by cleaning.
Replacing these fluids does not cause pain, but in most cases, it is not necessary.
John Paul is AAA Northeast Car Doctor. He has over 40 years of experience in the automobile industry and is an ASE-certified Master Technician. Write to John Paul, The Car Doctor, at 110 Royal Little Drive, Providence, RI 02904. Or email firstname.lastname@example.org and enter “Car Doctor” in the subject field. follow him on twitter @johnfpaul or on Facebook.