DEAR CAR TALK: Over the past couple of decades, wheels on cars have gotten bigger and tires have gotten shorter.
Why? It seems as though that would make cars ride rougher. — Randy
DEAR READER: It does.
There are two reasons for the wheel size wars, Randy. The main reason is looks. People like the look of a larger wheel filling more of the wheel opening. It seems silly, but if you go back and look at cars from, say the 1980s to now, the wheels actually do look kind of small.
So I guess it's the same reason my beehive hairdo went out of fashion. Tastes change.
The second reason for bigger wheels is better handling. That's simply a matter of physics. If the wheel is bigger, the tire's sidewall is shorter. And if the sidewall is shorter, there's less of it to flex and bend when you take a corner.
Now, if you're driving a 1987 Buick LeSabre, maybe you want shorter sidewalls to improve your handling. But if you're driving a 2018 Audi A4, you may find the car handles well enough already. And it may not be worth the trade-off of a harder, noisier ride. Not to mention a greater chance of a blowout and a bent wheel.
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DEAR CAR TALK: Could someone steal your catalytic converter while you are driving? If they had, like, a motorized creeper? Thanks. — Keith
DEAR READER: If a thief used a motorized creeper, followed behind you, accelerated under your car and stole your catalytic converter while you were driving, I'd say he deserves to keep it, Keith.
I mean, one decent-size pothole, and he'd be headless. If he succeeded, his fellow thieves would probably give him a silver star for bravery. Along with a Darwin award.
I'd say it's extraordinarily unlikely, Keith. Unless you live in Florida, in which case all bets are off.
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DEAR CAR TALK: I have a 2017 Ford F-150 3.5 Eco-Boost. One cold night this winter, I plugged in the block heater. The next day, I came down with a bad stomach bug and didn't leave the house the next two days. It never crossed my mind that the truck was still plugged in (not something you think about when you're making frequent visits to the bathroom).
On the third day when I moved it, I noticed a fairly large spot on the driveway. I checked all the fluid levels, and they were good. I assumed it was oil from the outside of the engine, but after about six days, the spot was gone (no rain or snow, somewhat low temperatures).
I didn't think oil would evaporate like that. The truck has been fine since this happened.
Here are my questions: Did I damage the engine by leaving the block heater plugged in for two days straight? What was the spot in the driveway: oil, radiator fluid or something else? Should I be concerned?
Thanks. — Troy
DEAR READER: No, water or coolant, and probably not.
You didn't do any damage to the engine by leaving the block heater plugged in for two days.
All the block heater does is heat up the coolant. And it doesn't even make the coolant hot. It just heats it up about 50 degrees or so, so it's not freezing cold when you start the car.
If you had left the truck parked outside during the summer when it was 75 degrees out for a couple of days, that would have been no different, as far as the engine is concerned.
So, what was the fluid that came off the engine? It's not oil. It's not transmission fluid. It's not differential fluid. Those petroleum-based fluids would never evaporate in a few days. If it had rained or snowed, maybe they'd get diluted a bit. But there's a reason they call them "oil stains," Troy. They're really hard to get rid of.
So I'm guessing it was either a small amount of coolant, which — because it's water soluble — could disappear over time, or it was water from some ice that melted when you warmed up the engine compartment.
And it's entirely possible that your small puddle has nothing to do with your block heater. You could have a loose hose clamp or a dripping water pump. You came out the other day looking for trouble. Maybe something's been leaking slowly for months and you just haven't noticed it?
If you see the spot again, see if it's got a greasy feel on your fingers. Coolant will feel slippery. It'll also have a sweet aroma and taste. Don't taste it, though, Troy, or you'll be trotting to the bathroom again.
If it's coolant, ask your mechanic to pressure test your cooling system. If there's a small leak, he'll find it that way, and you can fix it.
Ray Magliozzi dispenses advice about cars in Car Talk every Saturday. Email him by visiting cartalk.com