With cars, best to shoot for better-than-average rating

Dear Car Talk: Hi, I love your lousy radio show! I am 6-foot-3 with long arms, and am in my 50s, so things are starting to hurt.

I don’t fit well in most car seats — they’re too small for me and encourage a slumped posture that hurts my back.

I like the Ford F-150 seat; it lets me sit fully upright. However, I am seeing reports of poor reliability of the F-150 for the past 10 model years or so. Just how bad is the reliability? Thank you.

— Creaky Scott

Well, Scott, as recently as 2014, the F-150 got an “average” rating from our favorite consumer magazine — the one that collects extensive data on reliability.

That’s three out of a possible five stars. But even average isn’t that great. In terms of cars, we’ve found that most people are not happy with average reliability.

So we generally recommend that our readers and listeners try to buy cars with good reliability. Or at least better than average. Since 2014, the F-150 got two out of five stars for reliability one year, and one star all the other years. Oof.

The Dodge RAM 1500 had a couple of years when it reached up to three stars, but otherwise falls below that, too.

The Chevy Silverado gets mostly ones and twos. In contrast, since 2014, the Toyota Tundra got one three-star rating (in 2017), one fourstar rating (in 2016), and the rest are five out of fives for reliability.

If reliability is a priority for you, Scott, I’d see how you like the seat of a Toyota Tundra. But try to take a good, long test drive. Or ask if you can just sit in the truck for an hour, then see how your back feels.

Try out this spark plug switch

Dear Car Talk: I have a 2013 Camaro with the V-6 engine. When I changed the spark plugs, the old plugs from cylinders two to six were light tan in color, but plug No. 1 was dark and sooty.

The engine seems to be running fine. Is this a problem to worry about?

— Michelle

I’d worry a little, Michelle. When a spark plug is black, that’s usually a sign that there’s incomplete combustion in that cylinder. And when it gets bad enough, it’ll turn on your Check Engine light, and might even create a misfire.

You’re not there yet, but you’ll likely get there eventually. The cheapest and easiest thing it could be is a bad spark plug. If a spark plug isn’t firing hot enough or is badly mis-gapped, it won’t combust all the fuel and you’ll be left with a coating of black soot.

So now that you’ve replaced the plugs, check them in 30 days and see if No. 1 is getting black again.

If it’s clean the next time you check, then all you had was a bad spark plug, and you’re all set.

If it’s black again, then the next thing I’d test would be the coil. This car has what’s called “coil on spark,” where there’s a coil on top of each spark plug.

If that coil isn’t sending enough voltage to the plug, you’d get incomplete combustion.

It’s pretty easy to test a coil by simply swapping two of your coil packs.

Switch the coils from cylinders No. 1 and No. 2, and check back in 30 days. If your No. 2 plug is now getting black, then you’ve identified your bad coil, and you can just buy a new one for about $40.

If the blackened plug still shows up in cylinder No. 1, next on my list would be a bad fuel injector.

Each cylinder has its own fuel injector to spray in the precise amount of fuel at exactly the right moment.

If your No. 1 injector is leaking, or its spray pattern is messed up, too much fuel can be sent into that No. 1 cylinder, and not all of it will be combusted.

You’d test the fuel injector the same way you test a coil, by swapping two of them. But, unfortunately, getting to the fuel injectors is a lot more involved.

So if you’ve got a free weekend, you can dig in and try swapping around two of the injectors. Then check back in 30 days and see which plug is black.

On the other hand, if you’re going to go through the trouble of removing the intake plenum, the fuel rail and all the wiring, you might want to just go ahead and buy a replacement injector for $150 or so, and replace the No. 1 injector while you’re in there.

Once you’ve ruled out the plug and the coil, there’s a pretty decent chance that the injector is what’s causing your problem.