Life expectancy of modern spark plugs?

[scottmandue]

I had a 2000 Hyundai that ran up 80K or 90K miles, ran like a top, great mileage... but to the best of my knowledge I never changed the spark plugs.

I'm going to drive my 2005 Hyundai from L.A. to Portland OR Tuesday to give it to my wife, it has 70K miles on the clock. I will change the oil Sunday or Monday, car runs fine and gets great mileage but still has original spark plugs.

Just how long do modern spark plugs last?

I am from the old school where we used to do points, plugs, oil and filters ever 5000 miles... my how times have changed!

[aigel]

A lot of vehicles have plug changes required at 75-100k mile intervals. The engines run a lot cleaner and the contact metallurgy is very different where the contacts just don't erode much any more.

One day the hood will be welded shut. No maintenance for the life of the vehicle.


George

[aigel]

As far as your road trip goes, nothing to worry about. Even if the sparks are getting old, they don't just fail, leave you stranded. You'll get a little rougher idle and worse fuel consumption but that's it.

George

[Scuba Steve]

Originally Posted by aigel

A lot of vehicles have plug changes required at 75-100k mile intervals. The engines run a lot cleaner and the contact metallurgy is very different where the contacts just don't erode much any more.

One day the hood will be welded shut. No maintenance for the life of the vehicle.


George

I think there was a Honda ad a while back where they did just that... FWIW I don't buy into systems where no fluid change is recommended. That may be true if you rotate cars once they're paid off but for a couple of decades or more IMO nothing should be maintained that way. Spark plugs on the other hand... I don't remember the last time I saw an eroded one.

[David]

Our old '99 BMW 323i had 100K mile plugs. I changed them at 80K and there was a noticeable off idle improvement.

[A930Rocket]

My 01 F150 has 100k plugs. At $6-7 each, that's good and cheaper than my $12 P-car plugs.

[desertt5]

My Suburban with 100K got new plugs. Couldn't tell a difference with the new ones.

[Les Paul]

My wife had a Pontiac Grand Prix GTP with 175k. The front bank worn, back still good. Changed and no real improvement in mileage.

[aigel]

Originally Posted by A930Rocket

My 01 F150 has 100k plugs. At $6-7 each, that's good and cheaper than my $12 P-car plugs.

Mine had those too - the wires got old before the plugs did. It is a lot better with coil on plug now.

George