best spark plugs

the ac delco on line catalogue says 41-950, my owners manual says 41-900,the plugs in it when i bought it with 150000 miles were 41-929 plus they had a larger gap than.05....plus bosch and ngk seem to have a full range of " other " styles more easily available here..what does expierence tell us about the other products and the wide gap... news

From what Ive read the Northstar engine is VERY sensative to the plugs and wires used. When the time comes I will use what ever my local GM dealer says came standard in my car. I get 28-29 mpg on the interstate right now with my little old V8 and Ill wont do anything to mess that up! I think if you do a search on the subject you will see that 99% of the guys would do the same.

BKVic

I used Borg-Warner Select (magnacore helical) wires. The offer 10 times the performace of the standard carbon wires which loose their conductivity fairly quickly.
INFO: http://www.borg-warner.com/whatsnew/bwn15.html

I used NGK Iridium IX plugs...they have a 0.6mm core with takes a lot less energy to spark.
INFO: http://www.ngksparkplugs.com/products/cars_trucks_suvs/iridiumix.asp?nav=11420&country=US

With those and the wires, I get a spark every time and my gas miles is honesty 30-32 mpg on the interstate. I have tested it 3 different times. One time, on a 200+ mile trip and several other times on 50+ mile trips. City it is about 20-22 mpg. My aurora has never been smoother either. I didn't just test it with the information center... I actually calculated it from the trip OD and gas pump. It came out nearly the same as the Info center though (.2 mpg lower). My parents and brother couldn't believe me until they were with me when I tested it.

I changed mine at 75,000 miles:
When I was taking the delco wires out. There were at least 3 cuts in the insulation exposing the wire. One of them had slipped off the plug on its own and had built up a lot of carbon in the connection. Also 2 of them broke on me just trying to pop them off the plugs. The delco plugs were in great shape and looked exacty like they should. They really needed to be re-gapped though. They could have stayed in if I had re-gapped them but I love my NGKs.

There was a good article on why the OE ignition wires wear out quickly and hurt performance. I will try to find it and post it. The delco plugs are good also but they have a much larger core. But I definately do not recommend Delco wires unless they have a magnacore helical variety. The artical I read showed that standard OE standard wires have 50% of their original conductivity after only 60,000 miles.

O'rielly sells both of those or they can at least order them for you. The wires ran around $80 and the plugs were only around $5.50 each.

NGK products are great! Every one of their plugs have come out of the box perfectly gapped for the application. When I got my AC's, NGK showed no part no. for the car but these definitely look like they're worth trying. No wire set can withstand the underhood temps and vibration for much more than 30k mi. and it's not worth the performance loss to try and save money.

Here is the part number for the NGK Iridium IX plugs for the Aurora: TR55IX / The stock number is: 7164 / If anyone does not already know, the gap for the Aurora is 0.050

jessb, what is the stock number for the borg-warner select wires?

The stock number for the wires is CH7855. They sell them at O'Reilly but I am not sure who else sells them. You won't be dissapointed with these. Good luck!

http://www.oreillyauto.com/

Read my 6-20-04 post on Advice for spark plug and wireset.

i got the ch7855. i noticed there is also a ch7855sp. what is the difference? i tried oreilly.com, site was not available. the ch7855 cost more.

Was the sp available at the same place? I am thinking they are the same thing.

the sp are cheaper by about $15. the ch7855 i got are 7mm wire. though they are mag-core. let me know.