solman98

I ran the Plat 4's in my 5.7 for 3 years and no issues at all. Just don't make the mistake and try and gap them......

I'll consider them in the HHR when it's time to replace the plugs.

tazman

I am also a mechanic ( Acura ) and have never had a spark plug do what thay are stating. I have only had a spark plug burn prematurly do to heat. I wouls also do what was reccommended and put the original plugs back and see if the problem returns. That way that will have to go further and actually find the problem.

rhoss1

I had the bosch +4s in my 2.2l for about 5 months and 5000 miles later and no problems so far. (knock on wood)
rhoss1

Daverb

I have used Bosch platinum plugs in my old Dodge caravan and they lasted for 125,000 miles. I have platinum plugs in my HHR and have no problems.

solman98

All HHR's come with platinum plugs.

Black Beauty

Hey Daverb, I have a Dodge Caravan also,(1989 Turbo, 273,000 mi.) and I have the +4 plats too.
Small world...

Daverb

I know the HHR comes with Plats, but I have had no problems with them in the Caravan I had. Only got rid of the Caravan because i started to get around 9.5 to 10mpg with it. (and that was Highway) but then it had close to 300,000 miles when I traded. Even if it was still getting good gas milage, I would have traded it in for the HHR. Guess it was the Kid in me coming out again