My car recommends also colder plugs for highway/hot climates. The insulator
on my 'normal' plugs changes colour to dark brown. That's after a month
driving. Would a colder plug make the burn marks too?

"TeGGeR®" > wrote in message
...
> Abeness > wrote in news >
>> What size socket do I need for the plugs on a 94 Civic EX (D16Z6 engine)?
>>
>> Also, I notice that the service manual notes two different plugs, one
>> the NGK ZFR5J-11 for "normal" driving, the other the NGK ZFR6J-11 for
>> "hot climates or continuous high-speed driving". My car is used mostly
>> for trips, not a lot of local driving. Does primary driving at highway
>> speeds warrant the 6J plug?
>
>
>
> If you're spending much of your time at or near 4,000 rpm, you'll need the
> colder (6) plugs. Otherwise the insulator will overheat and blister.
>
> Pull the plugs that are in the car now. If the insulators have some color
> to them (doesn't matter what color as that's a function of your gas), then
> you're fine. If they are bright white with tiny bubbles on them, move up a
> range.
>
>
>>
>> Is another brand recommended? I just discovered sparkplugs.com--pretty
>> cool. Anyone bought from them? A listing of plugs for my engine:
>> http://www.sparkplugs.com/results_ap...1&AAIA=1168747
>> None of these manufacturers means anything to me. It's unlikely that I
>> need "premium" plugs--not a racer--but if the Champion Premium Gold plug
>> is any better than the NGK OEM spec, the price is certainly right.
>
>
> There are anecdotal reports of poor operation with anything other than NGK
> or ND plugs, the OEM spec.
>
> Personally, I've had unsatisfactory results with the "Splitfires". I don't
> know if this was just my perception or if the car really did run worse,
> but
> I didn't like them.
>
> Champion and Autolite are domestic manufacturers. GM and Ford use them.
>
>
>>
>> Since the last tune-up on this car was at 97K miles at an unknown date
>> (now at 118K), and since I don;t know whether the plugs were replaced
>> then, I'm thinking it might be a good idea to replace them soon.
>>
>
>
> Never a bad idea, that's for sure. You may find little wear on your
> existing plugs if they're platinums or if the car's spent much of its time
> at city speeds.
>
> --
> TeGGeR®
>
> The Unofficial Honda/Acura FAQ
> www.tegger.com/hondafaq/