Ask the AAA Car Doctor: Tires, check engine lights, and EVs

John Paul

John Paul

aaa car doctor

John Paul fields questions as the AAA Car Doctor. Email him for a personal answer and to see your questions in a future article here.

Q.         My wife and I recently helped our son purchase his first car, a 2022 Toyota Corolla Hybrid. I love everything about the vehicle (particularly all the safety features) except the stock Yokohama Avid tires. Don’t get me wrong, I think they are good all-season tires, but I would really like to replace them with some of those new “all-weather “tires when he drives home from college for the holidays in December. I like the idea of all-weather tires that are certified for winter use but that you don’t have to swap out for a second set of tires twice a year. I’ve done some initial research on Simple Tire and Tire Rack, and there seem to be quite a few choices. Obviously looking for the perfect blend of long tread life, wet/dry performance, not too noisy, and most importantly, stopping distance in winter conditions. The Michelin Cross Climate seems like a top choice but only starts out at 9/32 of tread and is pricy. Also considering Firestone WeatherGrip and Goodyear WeatherReady and General 365 AW. Any thoughts or recommendations?

A.         The only tires I have personal experience with are the Michelin Cross-Climate tires. They really do seem to be able to handle not only the snow but also cold temperatures which can affect not just ride and handling, but also stopping distance. The 9/32nds of tread depth is pretty typical of that size tire. Looking online, there looks like a $20 difference between the Michelin and the Firestone, I’m cheap but would spend the extra $80 for a set of Michelin tires.

Q.         My question on Honda’s vehicles a lot of times when you replace an alternator with anything but a DENSO alternator the dash charge malfunction light stays on. It doesn’t matter new or rebuilt by anyone other than DENSO.  Now, this doesn’t happen every time but pretty often. Any idea why? 

A.         There are times with certain cars that the original equipment alternator is the only part that works. Denso is the original equipment manufacturer for Honda and many other car makes. Honda uses a dual mode charging system and an electronic load detector. I suspect other brands of alternators that will in fact charge the battery but still have the battery light on are an issue with a slight design variations of the non-Denso unit sending a poor signal to the cars computer. Readers your thoughts? 

aaa car doctor
new car generator and belt tensioned on the shaft at shallow depth of field

Q.         We have a 2013 Honda Accord, and 2020 Honda CRV, my problem is that the low tire pressure light comes on quite a lot. Generally, about every three weeks for the Accord and seems at least once a week on the CRV the problem mostly involves the front tires.  Other than having the valves replaced, checking for flat tire issues, and having tires remounted are there any other solutions?  

A.         As good as some generally repair shops and dealerships are sometimes tire repairs are best left to tire shops. Most multiple slow leaks are cause by coorsion at the bead seal of the rim. This has become a more common issue with aluminum or alloy wheels, rather than steel wheels. Once the leak is determined to be coming from the bead area of the tire, the tire is dismounted, the wheel cleaned and then the tire reinstalled with a commercial bead sealer. Keep in mind all tires lose a little air each month which is why it is important for both tire life and fuel economy to get air pressure at least once per month. 

Q.         We have a 2008 Ford Taurus SE which we bought new; it has 121,000 miles.  It has been a great car; recently it has occasionally stalled when we are going slow as in taking a turn into our driveway or moving slowly in traffic.  Our usual repairman has checked it over, adjusted a few things, but it still happens. My husband asked a friend who he feels is a good source and he said couldn’t adjust the idle.  Do we need to bring it to a dealer or is it just “old age” like us?  

A.         The idle speed is controlled by the idle air control valve. This valve is a type of electric solenoid that adjusts air flow which in turn varies the engine idle speed. Over time this part can get dirty, sticky and be slow to respond to engine demands. Based on the symptoms, I would be checking and likely replacing the idle air control valve. 

aaa car doctor
Auto mechanic repairing car. Selective focus.

Q.         I’m trying to be more socially responsible in my life. Can you give me five things that I can do with my car that would help the environment? I’m not ready to buy an electric car yet. 

A.         Here are a few tips. Everyone likes a clean car but almost everywhere we are in drought conditions. If used regularly waterless car wash is an eco-friendly alternative to using water. The 3-month 3000-mile oil change is not needed with today’s engines and improved oil and filters. Never exceed the manufacturer’s oil change interval which can be as long as once a year or 10,000 miles.  Keep tires properly inflated and check them at least once a month, using a tire pressure gauge. Underinflated tires waste fuel and increase tire wear. Driving with a “check-engine” light on indicates a problem with the vehicle’s emissions system and depending on what is wrong can reduce fuel economy by 20 percent. Don’t use your car as a storage locker, extra weight can reduce fuel economy.  Chronicle your driving, most people drive the same routes each week, with a little careful planning it is easy to combine trips and reduce your mileage by 20-25 miles per week and saving a gallon or more of gas. 

Got a car question, email the AAA Car Doctor for a personal reply. [email protected]

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