2009 Yaris - Spark Plug Replacement Interval

[HarrySteph]

Have had a 59 Plate Yaris 1.33VVT since new - has 26k miles on the clock. It is used as a second car mostly around town to supermarket, etc.. For the past 6-7 years it has done an average annual mileage of around 1000.

My question is .......when should the spark plugs be replaced. Service company tries it on every year - wants £180 to do it, but the car starts and runs everytime without any problem. I've Googled the question and the answers vary - some saying between 30k-60k miles!? 

Does anyone know the answer, please?

 

[FROSTYBALLS]

6 years or 60,000 miles, whichever occurs first.

The answer will also be in the service & warranty book.

[Bernard Foy]

Modern plugs can work effectively for upwards of 60,000 miles no bother. I wouldn't be changing them before 50,000 miles. But I would have a look at them around 50K.

[FROSTYBALLS]

4 minutes ago, Bernard Foy said:

Modern plugs can work effectively for upwards of 60,000 miles no bother.

Then again the car is 13/14 years old.

[Mojo1010]

Put the reg in and buy from here Car parts for less

It's not a difficult job to DIY. If not able, pay a small fee for the local mechanic to do in the future. If the car still starts fine then can just continue for a year or so longer. Plugs are cheap. 

 

[Mooly]

I would leave them based on my experience. My Auris (same engine) had them changed at 60k and it would have been 9 years old. The originals looked as new at the all important tip, still needle sharp. I was amazed how easily they came out as well, a child could have undone them with no bother.

Be aware the original plug type is discontinued by Toyota and the SC16HR11 now replaces the original SC20HR11

Given your very low mileage I would leave them.

Our old 2003 Corolla (which was my dad's) has I suspect still got the originals fitted... mileage is low for its age but twice what you have done and these are also not Iridium plugs with such a long change interval. 

[TonyHSD]

Spark plugs usually aren’t a time interval replacement parts as they don’t age like rubber or plastics. However when left for a very long time they might become very difficult to undo and cause damage to the engine head threads when undoing is attempting.  At your low miles I will just leave them. 
All that if your spark plugs are the mentioned above Iridium type . If they are standard plugs then 30k miles intervals are fine and just about for replacement. 

[HarrySteph]

Thanks, everyone, for your response.

Much appreciated! 

 

[flash22]

09 1.33 is right around the time when they changed the plug heat rating - £180 seems steep for 4 plugs that are £12 each full retail - only use Denso plugs