When to change plugs?

Ryno · December 4, 2005

I have an 02 2500HD 8.1 4x4. I've changed everything else, but what about plugs and wires? I usually change them at 50k, it's got 54k on it now? Any favorites out there besides Bosch? I do std. plugs, no 4 pronged crap for me.

Haulin' 8.1 · December 4, 2005

I've got the same truck and I changed my plugs and wires at 50K also. I'm a professional tech so I don't wait for problems to arrise like most of my customers. They needed to be changed based on how they looked and the increase in efficiency I got from the change. An 8.1 easily burns 3 times as much charge in the same mileage as the average commuter car. So if you think your plugs are good for 100K then more power to you. You'll feel the misfiring at part throttle by then but they were losing ground long before you felt it.

Most guys on here stick with the AC/Delco plugs based on the if it isn't broke don't fix it philosophy. I went with Champion double plats based on my personal experience and driving style. I need the superiour heat handling capability of the patented Champion design. Speaking of which AVOID Bosch platinums on any engine that will see heavy loads whether it be towing, racing, speeding, whatever. Their super thin firing electrode WILL melt away until the gap is too large for the coil to jump and it misfires. They are great for mom and pop driving in a light duty engine but that's about it.

To increase milage and power I widened my gaps by 0.005" beyond the factory range. These new coil on plug ignitions will fire across it without a sweat and I don't leave my plugs in beyond 50K either so what I end up with is a larger spark that can ignite a thinner/leaner charge. Therefore it takes less fuel to operate.

I used Borg Warner wires because they always work well for me and the Delco wires were a lot more money. The ONLY aftermarket performance wire that is actually an upgrade would be Magnecore and I don't know if they offer a wire set for the 8.1. Avoid any wires from Autozone and Napa, too many problems.

Be sure to coat all boot interiors with dieclectric grease to seal them and allow for future removal. Anti-sieze on the plug threads should also be standard practice, espescially if you live in a rust prone enviroment.

Vernon

SS Crew · December 4, 2005

I hear what you say about fixing things before they become a problem, but as far a plugs go, I got 100,000 miles out of my '99 with a 5.3 engine in it. When I pulled them out they looked just like the ones I was replacling them with (stock AC plugs). There was no noticeable wear on either electriode.

I understand the 8.1 produces more heat, burns more gas than than the smaller engines, but this truck I pulled a 5000 lb boat and trailer across 200 miles of desert in the summer a dozen times a year the 4 years I owned the truck. I'm also not a real conservative driver. I really think that you could go the 100,000 miles on the factory plugs. But I would definitly change them at around 100,000.

Just my $0.02

SS

work'n 8.1 · December 5, 2005

The ONLY aftermarket performance wire that is actually an upgrade would be Magnecore and I don't know if they offer a wire set for the 8.1.

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T Bryne sells a set of Magnecore 8.5mm plug wires for the 8.1. Cost is $95. I don't know how competitve this price is compared to AC Delco or others, I haven't priced wires for the 8.1.

Bryan