Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Spark Plug Question

Hi all,

I have a 2017 Subaru Legacy 2.5L Limited with 57k miles. My next oil change is needed at 61k miles, and Subaru’s maintenance schedule requires changing the spark plugs. I am not mechanically inclined whatsoever, so I need to have either Subaru or an independent shop do this for me. I plan on having the local reputable shop do it, and was just wondering what an average price for a service like this would cost? I will ask for an estimate when I take the car in, but I would like to have some kind of a baseline idea of what they will most likely charge.

Any thoughts?


There are websites like RepairPal that can give you good estimates for where you live… you didn’t tell us where you live… and labor rates vary by as much as 50%.

The cost of spark plug replacement is the cheapest of maintenance. Worry about the big things.

live in Southeast Wisconsin.

Enter your info here, and you’ll get some idea.


Found an estimate - thank you, Tester!

Wouldn’t make more sense to call a couple of places you might use and get actual prices instead of internet guesses ? Also it is more important that the shop that does the work can be depended to do the work properly .

… including using ONLY the exact plugs specified by the vehicle manufacturer, in the Owner’s Manual. With a Subaru, this is likely a specific NGK or Denso plug.

1 Like

This is very important…Many independents use the cheapest plug like (autolite or champion). Do not use anything but Denso or NGK.

1 Like

For what it’s worth . . . I believe Autolite used to make some of the factory plugs for Ford

Not sure if that is still the case, though . . .

I guess my point is that Autolite is not necessarily junk, but it may very well be inappropriate for certain applications

For the past 25 years I’ve used nothing but Autolites in all of my Fords although I did deviate a few times and used Bosch when a particular Autolite was not available. Never an issue with either one.

I know it’s a bit fashionable to bash Bosch as making inferior spark plugs but I’ve never had or seen an issue with them as long as they are the correct ones for the application. Being a European car tech I’ve quite likely installed more Bosch plugs than anyone on the planet although db4690 I’m sure has had a hand or two in those jobs many times.

I suspect a lot of Bosch complaints come from people who think more (3 or 4 electrodes) is better so they install them anyway; hang the correct application. When things go south, blame the plug…

As for Champions, I quit using them decades ago except for lawn mower and chain saw applications. They caused me a lot of grief multiple times right out of the box.
As for Subarus, stick with the NGKs.

Almost always the best plugs are the ones recommended by the carmaker for your engine. Anything else is an experiment that may do harm and will rarely bring any practical benefit.

1 Like

It may not be junk…but it may not be correct either. The price difference is miniscule to not get the correct plug. But some independents have contracts with the plug companies. IMHO it may be worth looking into before I spent the money on labor.

I have no problems using Bosch plugs, if they’re the oem plugs for a particular application

To be so clear, that there can be no misunderstanding . . . if the owner’s manual lists Bosch plugs with such and such number, then I have no problem using them.

I don’t waste money installing bosch 4 electrode plugs in a model year 1992 Corolla that never came with them . . . and also won’t benefit from them

We stock some Champion plugs at work . . . for lawn mowers, weed whackers, onboard generators and a few other such applications


I’m not sure what you’re getting at with your previous comment . . .

I’m not using an autolite plug if it’s incorrect for the particular application

But I’m not going to make blanket statements, either, such as . . . autolite plugs are junk

I’m not dropping my car off an at independent shop for an ignition tune-up and telling them “I don’t care what brand spark plugs you install” . . . that’s not the right approach, in my opinion

I talked to one of my counselors yesterday and gave him some automotive advice. I told him to NEVER drop off your car at a shop with an open pocket book, so to speak. That’s what he’s been doing all these years, and he’s been taken advantage of several times so far. He had thought that was the only way to have your car worked on.

I’m not working on his car myself . . . He’s my counselor. We have a professional relationship. I also wouldn’t work on my dentist’s car or my gastroenterologist’s car. Completely inappropriate

Autolites have never failed me and I’ve always used what the car was born with at the factory both on my own cars and in a shop setting.

There used to be a chain of so-called tune-up places in OK City. They advertised a low price of X dollars for any 4 cylinder, a higher X dollars for any 6 cylinder, and an even higher price for all 8 cylinders.

We have had several people come in with a poorly running car after they visited one of these places and we discovered that what they were apparently doing is keeping removed spark plugs in huge boxes and selling used spark plugs. Just recycling spark plugs from one car to the other. Fit, heat range, long shank, short shank; it made no difference. The only requirement was that the plug screw into the hole.

A Subaru (which uses long shank plugs) came in once barely running after a visit to one of those sham outfits and I discovered that it had multiple types of spark plugs in it. Two holes had short shank A/C plugs, one hole had a Champion (long shank), and the remaining hole had an NGK with a cracked insulator. Not only that, but they had horribly cross-threaded all 4 of them and and it took me over 3 hours to remove the plugs and use a thread repair kit on all 4 holes.
I have two 1/2" air impacts (a CP 734 and an IR) and neither would budge those plugs out of the holes they were boogered so bad. It took a 30" long Cornwell breakover with a cheater pipe to force the plugs out. The guy really saved a lot of money by going cheap… :

I’m not saying autolite are junk. My wife use to own a Datsun 510…It had the NAPS-Z engine with duel ignition (4 cylinder with 8 spark-plugs). I tried Autolite plugs on that vehicle…Total disaster. I thought I screwed something up. Finally out of desperation I changed plugs to Denso. Problem solved. Autolite had a listing for that vehicle…but that vehicle was very particular as to what plugs it wanted. Not saying all cars are that way.

As far as I know Champion, Autolite and even AC/Delco have a plug listing for all gas engines on all manufacturers. So does NGK and Denso.

I agree 100%. But there are people that do. My brother is one of them.

1 Like

I seem to remember my sister-in-law once had a 4-cylinder Nissan/Datsun truck with 8 spark plugs

That engine was very very peppy. Faster then her next car (1987 Accord-lxi). But that Datsun was in the era of premature rust. It already had several rust through spots at just 5 years.

My brother’s Datsun SPL-310 had rust on the bumpers and other chrome parts in ~1 year.
If only the rust was the biggest problem that he had with that bizarrely bad car…

We sold my wife’s Datsun after 7 years and she had over 150k miles. The car ran flawlessly. We spent $0.00 in repairs. It was the last RWD vehicle we owned. Everything after that was fwd or 4wd or awd.

What model year was her Datsun?
IIRC, my brother’s (it was actually an SPL-311) was a 1968 model, and it was literally the car from hell.

We actually considered pushing it off a cliff at one point in order to collect the insurance money until we came to our senses and decided that we didn’t want to go to jail. After more than a year of nobody being interested in buying it–at any price–the father of our next-door neighbor bought it. We informed him of all of the huge number of mechanical problems that the car had, and–miraculously–he still wanted to buy it.