How low can you go with gasoline octane ratings?
Q: While traveling out West recently, I noticed 85 and 86 octane at some stations. What vehicles can run on such low octane?
— R.N., Manhattan, Illinois A: Nearly all cars can run on a lower octane at high elevations. The lower octane fuel (usually regular grade) is usually 100 percent gasoline. No ethanol. It is popular in the West, especially the high plains where the air is thinner (oxygen content).
You may have noticed that, although the octane was lower, the price was higher since ethanol in E10 fuel is federally subsidized. Although the EPA claims that your mpg drops about 3% when using E10, most motorists claim the difference is 8-10%. Lower octane, yes, but better fuel economy.
Q: Recently I bought a 2018 Honda Accord with pushbutton start. You just touch the button and let go and then the engine cranks until it starts. After many cars with conventional key-start, I really like this feature. One thing that I wondered about is what if the engine doesn’t start? How long will it crank until it gives up?
— D.N., California, Pennsylvania
A: When you had to turn the key to start the engine, you were warned not to crank the starter for more than 30 seconds to keep it from overheating. Cranking times are now taken out of your hands, and a computer program prevents overheating of the starter motor. In other words, it won’t keep cranking forever, or until the battery dies.
Q: I have a 2013 Prius C. I noticed a few tires losing air, so took the car to the dealer. I was told it is the valves. One tire valve was changed right away, but the other has the sensor stuck on it. They tried WD-40, and we let it sit for a few days. Taking it back, they were still unable to separate it. Thus I was told I have to buy a new sensor, which is $250. I told them that I would wait.
My question is, do I really need a new sensor? Is it that important when I manually check tire pressure anyway? I was told that this is a “wear and tear” item, which I have never heard. I really respect your opinion on this.
— B.B., Chicago
A: Once your car is beyond the original bumper-to-bumper warranty, anything that breaks is the owner’s responsibility. Your tire pressure monitoring system sensor has seized to the rim. If that is the case, it is almost impossible to remove without breaking. But new sensors are available for much less than $250. Check with an independent shop or tire dealer. If you maintain the tire pressure manually, you can get by without replacing the sensor.
Q: Are retread tires safe? When you drive down the interstate, you see tire remnants all over the road. Who has to pay for removing these pieces. The taxpayers?
— J.H., Chicago
A: Truck drivers call those slabs of tread rubber alligators, and they can be just as dangerous as the critter. Steer clear of them and keep your distance from the car ahead, lest it hits one and launches it at your car.
Retreads are a frugal way to keep trucks rolling versus new tires that can be expensive.
Because most trucks have dual wheels, they usually won’t stop until they reach a service plaza. The highway department is in charge of clearing the debris, but the ultimate charge is to the public.
Send questions along with name and town to Motormouth, Rides, Chicago Tribune, 160 N. Stetson Ave., Fourth Floor, Chicago, IL 60601 or motormouth .tribune@gmail.com.