Understanding tire specifications
I need to buy new tires for my 2013 Honda Accord. Because one of my current tires is relatively new, I’m hoping to buy just three. The one I’d like to hang on to is an offbeat, kind of expensive brand that I purchased in a rush after running something over. So, is it OK for me to buy three normal, standard-brand tires that don’t match it when I do my replacement? — Becky B.
It’s best to have four identical tires. However, if the new tires you purchase match the single tire’s specifications and have a similar tread pattern, they’ll do the job just fine.
While you’re checking things out, be sure to see if the single tire meets or exceeds your vehicle’s specifications. Accord service information specifies replacement tires should be 205/65R16 with a service description of 95H or better.
That first number, 205, refers to the section width (side wall to side wall) as measured in millimeters. The second number, 65, is the aspect ratio, in this case meaning the tire is 65 percent as tall as it is wide. The third number, 16, is the wheel diameter in inches. Finally, 95H refers to the load index and speed rating. In this case, 95 means the tire is rated to carry 1,521 pounds. A higher number here would indicate a higher load capacity. Meanwhile, the H means the tire’s speed rating is 130 mph. Letters that come later in the alphabet — with the exception of V,W, Y and Z — would indicate a lower speed rating. Watch out for this one!
Since your single tire likely has a bit less tread depth than the new tires will have, it’d be best to mount it on the rear of your front-wheeldrive Accord. Tires of differing tread depth and diameter cause undue stress and wear on a vehicle’s driveline components. This is a big deal on all-wheel-drive vehicles. What’s your take on the 3,000mile oil change my local oil changing place recommends? — Louie B.
I think it’s wrong to promote a onesize-fits-all oil change interval without taking into account how a vehicle is driven. A majority of modern cars and trucks employ a maintenance reminder or oil life system that considers many factors when indicating how many miles you can drive before getting the vehicle serviced again. Ambient temperature, average speed, run times, load and other factors are crunched by the system, resulting in a recommendation that could be much more generous than your local shop’s standard. GeneralMotors says the average recommended interval on its vehicles is 8,500 miles.
On a vehicle without a maintenance reminder that’s driven mostly for short trips, an oil change every 3,000 to 5,000 miles isn’t a bad idea, as sludge can build up under such conditions and cause problems. If the vehicle is usually driven on the highway for trips of at least 30 minutes, changing the oil every 6,000 to 8,000 miles or once a year— whichever comes first— is reasonable.
Also, synthetic oil holds up a lot better than dinosaur oil but it still gets dirty.
Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, Calif. Readers may send him email at under-the-hood(at)earthlink.net; he cannot make personal replies.