This is our first Volvo. We've had most of the common minor problems associated with this year models but love the car.

As we approach 30k miles, we hear from the dealer that new spark plugs are recommended. When I explained to the service writer at the dealer that over the last 12 years I have driven 7 different American cars a total of over 500,000 miles and have'nt bought one spark plug, he shrugged his shoulders.

Is Volvo engine technology such that they have'nt achieved the 100,000 mile tune up interval or is this just another way to make the dealers boat payment?

YMMV. (IOW, it depends.)

I stubbornly waited until nearly 37K mi on my original plugs. I'd noticed

the car had less part-throttle torque and put in Bosch Platinums. Big

improvement. I've replaced the BPs at ~ 30K since then. Tiny improvement.

The BPs seem to stay new-like much longer, apparently because the special

center electrode is protected from the heating/rounding that inevitably

causes conventional plugs' firing voltages to rise as they age. My car

came with "conventional" plugs.

Their "+4" (multi-electrode) plugs are not approved for turbocharged

engines.

I've also stubbornly (car failed to start a time or two), I mean,

scientifically tested my distributor cap/rotor to failure. 100K mi is the

outer limit. The 'contacts' were very pitted, and so much metal had been

transferred that plenty had been thrown in the circle the allowed arcing

to begin to become a problem apparently (img of cap follows on web site):

- Dave; '95 854T, 101K mi

Yes, spark plugs are due at 30K miles. This is easily verified by opening your users manual at the service schedule page.

Spark plug replacement interval has less to do with "engine technology" and more to do with how the manufacturer chooses to deal with the US EPA regulations. The interval is commonly 100,000 miles because that is the mileage that the EPA requires manufacturers to warrant certain aspects of emissions performance. Since a common source of faulty emissions is haphazard tuneups (e.g. wrong plugs installed), it is often easier to meet the requirements by delaying the first tuneup to that point. The fact that Volvo has chosen to deal with this differently has no bearing on the quality of their engines, which is superb.

Your owners manual should tell you the exact amount of miles you should go between spark plug changes for your model year......I would follow that, and forget what your dealer/service manager says, unless there is a very good reason for not going with Volvo’s numbers.

S. Ferraro

Hoboken, NJ