May 5, 2007I installed AC-Delco Iridium spark plugs in my 2000 4X4 Silverado last week on advice I got about improving horsepower and fuel mileage. As soon as I installed them, I could notice the new "pep" my truck had. That same weekend, I took a trip to the beach and checked my mileage down there and back. I averaged between 16 and 17 mpg. Before my tune-up, I averaged about 14 and 15 mpg. I paid about $7 per plug, but I think it was well worth the extra money!
Forums : Performance General : AC-Delco Iridium Spark Plugs (288 Views)
Subscribers : 04 GMC ECab
May 5, 2007Same plugs I purchased for my 04 after reading the comments on here. Haven't put them in yet, I have 85,000 on mine. They are costly.
May 6, 2007True, the plugs are pretty expensive, but with the improvement in performance that I had with my Silverado, I would have to say, money well spent!
May 6, 2007I have to laugh when I hear about someone saying "more power, better mileage, or better throttle response" after installing plugs. Your replaceing the plugs for a reason, they are warn out!.
No offence intended, but seriously,... Glad it is running great.
May 6, 2007I put in NGK iridiums a few months ago. Don't regret doing it, but no noticable difference in the engine....
May 6, 2007i had those stock on my tahoe when i replace them with a new set the performance was the same i didn't notice any differce
May 6, 2007Scoff all yinz want.. Irridium Plugs do perform better than other types. Thats why GM uses them in all new vehicles.
Advantages of Iridium spark plug types
Due to the properties of Iridium, the spark plugs center electrode can be made with a much smaller diameter than with platinum, Gold or gold palladium and copper/nickel types without sacrificing service life. The spark plugs potential difference is more concentrated at the tiny Iridium tip and hence less 'spark jump' voltage is required - this can be as much as 5,000 volts less than with standard plug types. Ignition is improved and less strain is placed on the ignition system. Benefits of improved ignition/combustion include better fuel economy, increased power/acceleration and especially better throttle response.
May 7, 2007Anyone have the Iridium plug part# for 96-99 Vortecs
May 7, 200712571164
SUBJECT: INFORMATION ON NEW SPARK PLUGS AND GAPPING
2004 Buick Ranier
2002-2004 Cadillac Escalade, Escalade EXT
2003-2004 Cadillac Escalade ESV
2004 Cadillac CTS-V
1997-2004 Chevrolet Corvette
1998-2002 Chevrolet Camaro
1999-2004 Chevrolet Silverado
2000-2004 Chevrolet Suburban, Tahoe
2002-2004 Chevrolet Avalanche
2003-2004 Chevrolet Express, TrailBlazer
1999-2004 GMC Sierra
2000-2004 GMC Yukon, Yukon XL
2001-2004 GMC Yukon Denali, Yukon XL Denali
2002-2004 GMC Sierra Denali
2003-2004 GMC Envoy XL
1998-2002 Pontiac Firebird
2004 Pontiac GTO
2003-2004 Hummer H2
with 4.8L, 5.3L, 5.7L or 6.0L V-8 Engine (VINs V, P, T, Z, G, S, N, U -- RPOs LR4, LM4,
LM7, L59, LS1, LS6, LQ9, LQ4)
A new spark plug has been released for use in the above vehicles. The new spark plug has an
Iridium tip instead of the current Platinum tip. Due to the different tip design, the gap of the
spark plug has also changed. The new spark plug, ACDelco Part Number 41-985 (12571164), is
gapped to 1.01mm (0.040 inches) when the spark plug is made. The spark plug gap is set during
manufacturing and should not be changed to the gap required with the Platinum plug, or damage
to the spark plug may result.
GMParts Direct has then for 5.10ea