Best Spark Plugs for Subaru: Outback, Forester, Legacy & Impreza
So, it’s time for spark plug replacements. Your Subaru’s waiting, but you’re still dwelling on what the best choice actually is.
That’s a rather easy answer from me.
The OEM manufacturer of all Subaru spark plugs is NGK. This applies to literally anything – from that Subaru Forester 2.5, to an Impreza, Legacy or Outback.
Now, what matters here is the year of your car. For example, these NGK spark plugs fit roughly all Subaru models from 2013 to 2017.
Older models, however, have platinum plugs as an OE.
If you have a 2000 to 2003/4 Subaru: You most probably need these G Power plugs. They fit:
Subaru Outback (both Base and H6)
Subaru Legacy and Legacy GT
Subaru Impreza and WRX (up to the 2005 models)
You can still put iridium plugs on these older models, but I advise you to stick to the platinum G Power you had installed when you got your Subaru.
I’m not sure about the exact year when they went from platinum to iridium. However, it should be around 2005.
For example, this NGK 7913 plug is the OEM for:
2005-2009 Legacy 2.5i, 3.0 R and Legacy GT
2005-2009 Outback 2.5, 3.0 and XT
2009-2013 Forester X
2009-2013 Impreza 2.5, WRX and STI
And it’s an iridium plug once again! So it seems the dividing line is 2005, after all.
Is NGK the only choice?
No, obviously not. There are other brands like Champion, Denso, Bosch, Autolite…
If I were to recommend one of them as an alternative, it would be Denso.
Both NGK and Denso are huge OEM suppliers for most Japanese brands. I’ve written about them in my article on Toyota spark plugs too. However, as you can see in a lot of Subaru-specific online communities – like the Outback forum, NGK is the most optimal choice.
NGK's most long-lasting spark plugs. OEM fit for newer Subaru models, excellent quality.
What is the right gap on Subaru spark plugs?
So, one of the first things you have to remember is the factory gap on Subaru cars.
As you know, every spark plug sticks to a specific electrode gap.
With Subarus, the gap is flexible and ranges from .039” to .044”. This means that as long as you are in this range, everything will run smoothly.
Note that platinum and iridium plugs usually come pre-gapped. You don’t need to mess with them, and you’d better not – given how sensitive the iridium or platinum tips are. Just check whether they’re properly gapped. Most of the time, they are.
This gap is actually shared among most Japanese car brands. Hence, you’ll see a lot of interconnecting NGK spark plugs for anything from a Subaru Legacy to, say, Toyota Camry and Honda Accord at the same time.
I’ve heard that some people go over the .044” limit a little bit, as long as they use copper plugs. This is due to their better conductivity, which allows for some leeway. It’s an option, I guess, but I wouldn’t experiment with that too much.
Speaking of copper…
Is it worth it to go for the iridium spark plugs on my Subaru?
This has always been a huge debate, and not only limited to Subaru owners.
Look, some people dislike iridium because it’s several times more expensive than copper. Heck, it’s even easily double the price of platinum spark plugs too.
It’s all about the tradeoff between price and convenience, to be honest.
You get the iridium NGK plugs and they could easily last you for some 80 000 miles or so. This means you save effort on changing them every 20k-30k miles the way you’d do with copper parts.
For some, that’s pretty much worth it. Some people love DIYing a lot, others dread the back spark plugs which can be tough to reach. A set and forget iridium spark plug saves them the frustration.
On the contrary, copper plugs score higher on conductivity. Also, if you have an older model – say, a 1996 Impreza or a Subaru Legacy 1999, there’s a big chance your vehicle won’t jive well with iridiums.
In the cases of 90s models to very early 00s, a lot of the Subarus back then ran on the classic NGK V Power.
This is the classic copper OEM spark plug. Cheap, well-performing and the perfect fit for a lot of Japanese cars.
Classic copper spark plugs for older Subaru models. Cheap, more conductive, but will last 2x/3x less than newer NGKs.
What about the spark plug wires?
Things here are quite similar to my recommendations for your Subaru’s spark plugs.
You can either go with NGK or, alternatively, with Denso.
However, Subaru themselves also have OEM spark plug wires like this set here:
I’d say either go with that or pair your NGK plugs with wires from the same manufacturer. Just make sure you double-check your car’s model year.
For example, the above OE kit fits 2005-2010 Forester (non-turbo), 2005-2011 Impreza, 2007, 2008 and 2009 Legacy etc.
Is it that difficult to change my Subaru’s spark plugs by myself?
Well, it is…and also, it’s not. If you would ask me on a scale from 0 to 10, I’d give it a 5.
If you feel intimidated, you can always grab your set of spark plugs and take it to the local car guys. Amazon usually gives better prices compared to local dealers, though.
But what if you’re up to the challenge? Well then, YouTube is one of the best places for you, as there are plenty of pretty great tutorials on how to change the spark plugs of Subaru cars.
This one is especially educational and easy to follow. While it involves the 2000-2012 Subaru Outback, the process is similar to other models too:
That’s all for now, I guess. Any questions – just shoot ’em in the comment section below.
If you’re in full DIY power mode on, be sure to also check my article on Subaru brake pads. Once again, I’m talking about the best OE replacements out there. A Subaru was born to be wild and outdoorsy – and all of its aftermarket parts should work to help it reach its maximum potential.