Changing plugs - how often?

[--tom]

My volks lupo has run on the same plugs for perhaps 3 or 4 years and there are no problems or low mileage. I change the oil yearly but should i now change the plugs or leave well alone?
If i change the plugs whose make of plugs should i use?

 

[Diyisfun]

What does it say in the service manual?

 

[Scoby_Beasley]

I always clean and reset plugs at 6000miles or four months. Then I change them about every 18 months, not essential if you clean and re-gap on a regular basis.
I'd always go for Bosch which used to be O.E. on VW's anyway. I've had problems with the ceramic part breaking off / cracking with NGK plugs on more than one occasion, never happened with me Bosch though.

 

[Percy Vere]

According to my car dealer, plugs are so long lasting these days that they should last for 2 years or 24,000 miles whichever is first.

 

[fido]

I would keep using them until you have problems, like difficult starting or lumpy running. As long as the engine is firing on all cylinders the old plugs will not be harming your engine. Regular oil and filter changes are the most important service item. Some drivers are not aware that a blocked oil filter is the same as no oil filter as there is a bypass valve which allows oil to divert away from the filter if it is choked.

 

[pipme]

Be interesting to see how the 18,000 mile twixt service vehicles perform in their twilight years. There seems, in the short term, little or no difference in the oil itself ... Plenty of caveats in the Renault handbook .. short journies, slow running etc reducing the mileage -- Who reads that?
I think 18k is too far .. 9k on my Nissan is about right, regarding disc pads etc etc. and 6 years of ownership from new.

We shall see.

 

[fido]

This seems to be something the oil companies have allowed to slip past the net. They are very powerful and usually quick to stamp on any practice that could adversely affect their profits. I suppose the high prices charged for modern oils like Mobil 1 may partly be set to take account of the reduced demand resulting from extented service mileages.

 

[pipme]

Cheaper to replace engine than change oil soon !!