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By the way, if I also drive this one for 27 years, I will be 100 and still driving it. Thanks for any suggestions or help. —Fran

I’ll need a crane to get myself into a Miata when I turn 100. I’ll certainly need one to get me out.

When you go over a speedbump, Fran, you’re causing the suspension to go beyond its normal limits. And strange things happen when you push components that far. So finding the culprit — without convincing your mechanic to hang by his fingers under your car while going over a speedbump — is going to involve some guesswork. What could be making noise when pushed past its limits? It could be something like your control arm bushings, which are involved in letting the wheels move up and down without letting them move forward and back.

Next time you’re in, ask your mechanic to start by spraying your four front control arm bushings with silicone penetrating oil. If that doesn’t help, try the rear bushings next time. Ideally, you want to know what fixes it, so you’ll know where to spray when the noise comes back. Don’t spray the convertible top, though. I think we can rule that out.

Another possibility is that the car itself is flexing over the speed bump, and the spinning driveshaft is momentarily scraping against the exhaust system. That’s not uncommon.

If the plugs were easily accessible, you could just loosen them and then tighten them back up — just to make sure you could remove them if you ever had to. But with the amount of work it takes to get to the rear plugs on your RAV4, you’d be crazy to do all that labor and not just replace those plugs for the additional $81.

So, as a responsible mechanic, and one with an IRA to fund, I have to recommend you go ahead and change them. Especially if you plan to keep this car for the long haul. But as a consumer, I can certainly see why you’d be tempted to take your chances, John.

I’m sure it’s possible, Wayne. Even though it’s not nearly as easy as testing a D-cell that powers your flashlight or monitoring the charge on your iPhone. Because a 12-volt car battery has to provide a massive amount of power all at once to start the car, you really have to measure the resistance of the electrolyte.

There are testers you can buy and use at home that claim to test your car battery and cost anywhere from $20 to $200. But if you want one that gives you the same information that we get at the shop when we test the health of car batteries, you’re probably going to spend at least $100-$150. That may make it cost prohibitive to include as standard equipment on every gasoline-powered car.

Of course, with the costs of electronics and computerization dropping every year, that calculation may change, but possibly not before electric cars take over and make this whole issue of the “starter-battery” moot.

So in the meantime, if you don’t want to get stuck with a dead car battery, my advice is to replace your battery every five years. In my experience, batteries rarely die before the five-year mark. But after that, they’re essentially on borrowed time. You may say, “Well, why should I spend $150 on a battery if my old battery’s not dead yet?” And the answer is, because it’ll still cost you $150 six months or a year later, plus the towing fee, the inconvenience, the missed dinner at your daughter’s house, and the indigestion from having to eat at the Only Dropped It Once Burger at a highway rest stop.

Again, the point is that drivers should not be trying to decide on the spot which laws they should or should not follow. They should instead assume that a lot of thought, over long periods of time, by a lot of people, went into how the law was written and why, and that their real-time decision on whether or not to follow them might not consider all those reasons. Thanks for listening to my rant! — Brad

I can’t argue with you, Officer Brad. Keep in mind that traffic laws vary from state to state. They’re enacted and enforced by each of the states individually, not uniformly by the federal government. After all, you get pulled over by the state police, not the national police, right?

And while I’m fairly certain that “appropriate signaling” is required by statute in every state, it would take me a ton of time to read every state’s traffic laws in order to confirm that. And I have a personal law against spending more than three weeks answering any one question, Brad.

Here’s why. The F-150 has a 3.5-liter V6 gasoline engine that’s tuned to work with a 47 hp electric motor. Around town, the truck makes good use of that battery-powered electric motor, using it for lots of the typical stop-and-go driving that ruins gasoline engine fuel economy. When you need more power, like when you want to accelerate quickly or if you’re pulling a heavy load, the gasoline engine kicks in, too. But in stop-and-go traffic, the electric motor does a lot of the heavy lifting.

On the highway, things are reversed. You’re primarily using the gasoline engine, with a boost from the electric motor when needed, like when you’re carrying a horse trailer full of in-laws to a family reunion.

If you want to get a general sense of where the hybrid powertrain helps the most, just compare the hybrid F-150 to the regular F-150. A non-hybrid four-wheel drive F-150 with a similar 3.5L V6 gets 18 mpg city (vs. 24 city for the hybrid) and gets 23 mpg highway (vs. 24 highway for the hybrid). So the hybrid improves the highway mileage by about 4% but boosts city mileage by 33%.

Car redesigns have never been on such a rigid schedule. In the old days that you’re probably referring to, the 1950s and ’60s, the manufacturers did make a big deal every fall about “next year’s new models.” But in reality, that often meant a tweak of a taillight or a new piece of trim. The real, mechanical guts of the car were not changed every year. Or every other year.

The truth is that the complete redesigns — new platform, new engines, new interiors — are all over the calendar. And while product life cycles are shorter today than they’ve ever been, the average vehicle is still only redesigned once every six to seven years. And there’s no general assumption you can make about when that will happen. You’d have to check each manufacturer’s product schedule.

Top-selling cars get more-frequent updates. Poorer-selling cars get ignored for years on end, because the costs of redesigning them may never pay off. And pickup trucks don’t get redesigned that often, because their buyers aren’t as eager for change. To make things more complicated, some manufacturers stagger different types of major improvements.

If your Outback had a manual transmission, you could argue that she’s putting extra wear and tear on the clutch, and that brake pads are cheaper than clutches. I’d still probably tell you to leave her alone, in the interests of domestic bliss, but at least you’d have a theoretical case to make. But with an automatic transmission (or a continuously variable automatic transmission like you have), there is no clutch. In fact, your car doesn’t even have any gears. A set of belts slides up and down a cone-shaped device to increase and decrease the gear ratios “variably” as needed. The paddles on the steering wheel just “mimic” gears by causing the transmission computer to jump to preset gear ratios. So the primary reason the paddles exist is so you can have fun and pretend you’re shifting gears. And that’s what your wife is doing.

I understand that the sound of the engine can be a little annoying, Terry. But rest assured, no harm is being done. I’m guessing she’s just a little bored with your 2014 Outback and is trying to spice things up a bit. So if you want her to stop, try making more scintillating conversation when you’re in the car with her.

So when Toyota’s engineers built the Prius, they could either grab all that 12-volt stuff off the Toyota shelves and put it in the Prius, or they could start from scratch and design a whole new set of electrical components to run on high voltage. Not surprisingly, they took the easier route. Why spend time designing a new windshield wiper motor when you’re already reinventing the propulsion system?

And that’s why there are two electrical systems in your Prius. One is a 12-volt system that runs all the traditional electronics. The other is a high-voltage system that powers the wheels and the motor-generator that starts the gasoline engine.

OK then, you may ask: If the high-voltage battery runs the motor-generator, which starts the gasoline engine, why can’t I still drive my Prius when the 12-volt battery is dead? It sounds like I don’t need the 12-volt battery to start the gasoline engine.

Yes. I can tell you, with 100% certainty, why it never goes into 10th gear, Denny.

In terms of fuel economy, you’re not alone in failing to achieve the Environmental Protection Agency’s fuel economy rating for your car. The EPA even says that their standardized mileage tests are primarily for comparison purposes, allowing you to see how similar cars stack up against each other. Those tests are performed under what we call “ideal conditions,” that most of us will rarely duplicate.

Oddly, some cars we test DO manage to get their EPA rated mileage or very close. But most fall short. Some by a wide margin.

The only possible area for improvement is your tires. First, make sure they’re not overinflated. Overinflated tires will definitely add more bounce to the ride, and that’s the last thing you want. Don’t underinflate them either but go to the low end of the recommended pressure range, especially when you’re not towing anything.

And when it’s time for new tires, shop with comfort in mind. Because so many “off road” vehicles never go further off road than the Wendy’s parking lot, tire makers have started making off-road tires that are really on-road tires.

They call them — are you ready for this, Carl? — On/Off Road All-Terrain tires. But they function like on-road tires, recognizing that for most people, off-road ability is more fashion than function. These hybrid tires are designed for people who buy an off-road truck because it looks cool, and then realize they hate every minute of driving it because it rides like an off-road truck.

So you might look at something like the Continental Terrain Contact A/T, for instance, which gets a pretty good rating for comfort, along with everything else. And that won’t reduce your towing capacity, as long as the tires carry the ratings your truck requires. But don’t expect a miracle, Carl. Less off-road-y tires will help, but you’ll still want to wear that mouth guard when driving.


Not common at all. Back in the early days of turbos, like in the 1980s, it was not uncommon to have a turbo seize up after 75,000 miles or so. Turbos weren’t well cooled back then, and oil would get caked onto the hot turbo and cause its bearings to fail.

But that problem was solved many years ago. Oils are far better, turbos are better and it’s pretty common for a turbo to last the life of the engine now. So you’re well within your rights to be disappointed in the performance of your Buick, Jeff.

But the biggest safety advances are electronic. The 2021 Prius comes with what Toyota calls their Safety Sense package. That includes automatic emergency braking. So if you’re distracted watching your mileage tick from 53.4 to 53.5 and don’t see a car stop in front of you, the Prius will warn you to brake and will even brake for you if you don’t react in time. The system senses pedestrians, too. The 2021 Prius warns you if you start to drift out of your lane on the high-way, and even nudges you back into it.

It alerts you when someone is driving in your blind spot, so you don’t change lanes into a Tombstone Pizza truck. It has a backup camera, and it warns you if a car is coming down the street from either direction as you’re backing out of your driveway. It also has a head-up display, which projects your vehicle speed through the windshield, so the information appears to be floating at the end of your hood. That allows you to know how fast you’re going (and see your GPS turn directions) without ever taking your eyes off the road.

— Charlotte

I think you have a problem with the motorized tailgate, Charlotte. How’s that for blazing insight? I’m not sure what it is, but I know that Toyota had problems with the computer that controls the power back door. And yes, Charlotte, there’s an actual computer that controls your power back door. What a time to be alive, huh? Toyota even offered to replace the computer (called the PBD ECU or the Multiplex Network Door Computer) for free for customers who had malfunctioning rear doors.

The primary complaint from customers was that they loaded something that was too big for the rear compartment and then closed the rear liftgate. The door closed and stopped when it got to the obstruction, as it’s supposed to do, but then it wouldn’t function after that. Your problem sounds a little different, but we’ve seen another service bulletin that said when a certain trouble code comes up in a scan (that’s what your dealer did when he “checked it with their computer”), the solution is also to replace that back door computer.

I would guess the part itself costs about $150, and there’s not much labor involved. It’s two bolts and a couple of plugs. But if you first complained about this while the car was under warranty, they owe it to you for free.

I know it’s intimidating when other drivers try to bully you into going faster than the speed limit. But you have the right to travel in the right lane at the posted speed. You’re being a good, courteous driver.

I do worry about you, though. There were studies done that concluded that speed differential causes accidents. In other words, it’s not driving at 75 that necessarily causes people to crash, it’s when some people drive at 75 and others drive at 50. So, depending on your state law, my suggestion is to make good use of your hazard lights.

Hazard light laws are, frankly, a mess. Some states allow you to use them while driving. Some allow their use while driving if there’s a traffic hazard (which is your situation). And some states only allow hazard light use if your vehicle is stopped or disabled. So you’ll have to check your state law (try a local AAA office).

Either way, if you see an emergency vehicle on the shoulder, first try to pull into the center lane, if it’s safe to do so. And then let people pass you if they want to. Just ignore them if you’re going 70. If you can’t get into the center lane safely, then follow the law and slow down, and if state law allows, put on your emergency flashers while you’re traveling at 50 mph.


Check out the RTD Weather Desk to see what’s in store for the Richmond area and John’s take on what the forecast means.

Well, make sure you have your hair piece glued on really well, because the first thing to break will be the hydraulic mechanism that puts the convertible top back up. The problem, Richard, is that there’s really no way to fully prepare for an adventure like this. You’ve covered yourself for 15 or 20 things that can go wrong. But there are thousands of things that can go wrong. And it’s simply impossible to anticipate them all. And Murphy’s Law (which is called Mercedes Law in Germany, by the way) says that what does go wrong will be something that requires a part that hasn’t been in production since 1998.

So you have to make a choice. Either you want the adventure of making this trip, with all the thrills and potential tragedies and stories to tell that come along with it. Or you really just want to get the car home, in which case you can pay a car carrier $1,200 to trailer the car home for you and discover what’s wrong with it while staying within “Hi hon, can you come pick me up?” distance.

If you really want the adventure, then accept that it’s largely unpredictable, and you may get stuck for a month waiting for parts in Wyoming. If I were you, I’d plot out any Mercedes dealerships between Minnesota and Oregon on a map and plan a route that takes you right by every one of them. Finding someone who can work on this car and getting parts may be your biggest challenges if you have an unusual problem.

It could be any number of things, Marsha. But I suspect you have a vacuum leak. The engine naturally creates vacuum every time a piston descends and sucks fuel and air into a cylinder. That “free” vacuum power is then used by other systems in the car. For example, it’s used by the ventilation system to control the flaps inside your ducts, and by the exhaust gas recirculation system to open and close the EGR valve.

If you have a vacuum leak, that means unwanted air is leaking into the cylinders. Because the mixture of gasoline and air in the cylinders has to be just right, a vacuum leak throws off that delicate balnce by letting in too much air making the engine run rough.

There are various ways to find a vacuum leak. If it’s big enough, you can sometimes hear it hissing. If not, we sometimes spray combustible fuel cleaner where we think air might be leaking in. If there’s a vacuum leak nearby, that fuel cleaner will get sucked into the cylinders and we’ll hear the engine rev up. Or we pinch off individual vacuum hoses, one at a time, to see if closing one off makes the engine run smoothly.

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