Technical Spark Plugs

[jameshobiecat]

Why on earth do fiat advise changing spark plugs every year when other manufacturers say they last 60k miles or more?

Modern engines have near perfect air fuel ratio at all times so they should last. I bet they look like new when removed after twelve months.

My theory is that fiat have aways said that and have not updated their advice in decades.

I think I will give my plugs and annual check and only replace every few years.

 

[DlightSwitch]

I changed mine after 25k miles, 2 years and they definitely needed doing, pretty sure they hadn't been changed before. I'd rather follow the guidelines and do them when Fiat tell me to, but if you want to inspect yours and have second thoughts that's up to you, at least you're still taking care of it

 

[dave]

they only cost a few quid, you get that back in the extra mpg

in the old days you would clean once a year but that is now known to be bad and they should be replaced instead

 

[jameshobiecat]

I'm sorry but I can't fathom why they last 60k in a peugeot and only 12k in a fiat.

 

[dave]

I'm sorry but I can't fathom why they last 60k in a peugeot and only 12k in a fiat.

fiat prefer you to have an engine running at maximum efficiency and not leave you broke down in the rain because of a failed plug, they might last to 60k in a fiat but will be using more an more fuel

 

[Andy Monty]

I'm sorry but I can't fathom why they last 60k in a peugeot and only 12k in a fiat.

i'd check your service book for the intervals on servicing... IIRC its 18K miles or yearly rather than 12k

4x plugs cost about £12 for NGK at our local factors changing them takes all of 20 mins

 

[grantewhite]

My car has just had its 30k service including plugs and my friend (who works at fiat) said that the plugs were "fukd" when removed, also if you look up the original fiat part for the spark plugs you will find that they are a lot more that 12 quid unless you wanna get cheap crappy ones , since changing mine the car feels a little more responsive and runs better so all in all a good idea id say.

 

[Andy Monty]

Err since when were NGK cheap crappy ones? NGK are the same as what fiat supplies you with their own name stamped on in a different box

 

[Magic Johnson]

My sister's Fiesta had original spark plugs despite being 12 years old and on 80k LOL. She found this out when she put it in for a service. Shows you how well people look after cars eh?

I get them done annually though, regardless of what the manufacturer recommends.

 

[jameshobiecat]

Ok let me put it another way; do fiats eat spark plugs far quicker than other engines?

 

[dave]

No

 

[Magic Johnson]

Ok let me put it another way; do fiats eat spark plugs far quicker than other engines?

Christ they cost £12! Your tighter than a Scotsma...oh wait.

 

[jameshobiecat]

It is not so much the money (i'm not a scot despite the name), i'm more interested in why fiat differ so much from other manufacturers on this.

 

[D4nny8oy]

Where plug-change intervals are quoted as 60k, it's usually due to the manufacturer specifying expensive platinum/iridium-tipped versions which have a longer lifespan.

Copper-based versions are cheaper but have a service life of 10-20k, and whereas Fiat service intervals were 12k (with plugs being changed at 24k), now the 18k intervals mean the plugs would end up being well outside their optimum working lifespan (at 36k for the second service), unless you'd rather have to pop in to have have them changed between services?

From experience, NGK plugs are more evenly balanced resistance-wise than others, like Champion for example, which means a more consistant charge and discharge output needed from the coils.

 

[jameshobiecat]

Where plug-change intervals are quoted as 60k, it's usually due to the manufacturer specifying expensive platinum/iridium-tipped versions which have a longer lifespan.

Copper-based versions are cheaper but have a service life of 10-20k, and whereas Fiat service intervals were 12k (with plugs being changed at 24k), now the 18k intervals mean the plugs would end up being well outside their optimum working lifespan (at 36k for the second service), unless you'd rather have to pop in to have have them changed between services?

From experience, NGK plugs are more evenly balanced resistance-wise than others, like Champion for example, which means a more consistant charge and discharge output needed from the coils.

Ah now we are getting to it, Fiat fit cheap spark plugs. is this true for t-jets? I have read that their plugs are much more expensive.

 

[DlightSwitch]

Ah now we are getting to it, Fiat fit cheap spark plugs. is this true for t-jets? I have read that their plugs are much more expensive.

Don't think so, T-Jet OEM ones are NGK Iridium tipped, that's what I replaced mine with

 

[D4nny8oy]

Ah now we are getting to it, Fiat fit cheap spark plugs.

As do many manufacturers as it means a lower service cost.

Platinum/Iridium tipped plugs may last longer, but they're easily damaged. For example, T-jets can eat through them very quickly if used for a lot of short journeys.