I vote Iridium and AC delco, ngk or autolite

 

I had ac delco plats .. also OEM factory plats ... the platinum melted off the plug tip vaporized.. so I using forum recommendations installed the Iridium plugs ..at 30 to 40K miles the plats got melted so with the Iridium plugs I checked at the 40K miles and plugs looked like I just put them in .. been in there now several years... perhaps 80K miles now on them.. some reported they lasted 200K miles..

ON my toyota truck they are factory Iridium plugs and manual says 100K miles is the normal plug replacing .. some go higher like 130K and found the plugs still looking good..

ac delco I have in there so I would recommend that manufacturer .

 

x3....On Going with A/C Delco Iridium Plugs, Also Check the Plug Wires, and if They Haven't Been Changed Out in a While This Would be a Good Time to Install a Fresh Set, and If you Go with A/C Delco Iridium Plugs, Keep in Mind that the Spark Plug Gap is Set During Manufacturing and Should NOT Be Changed or Damage to the Spark Plug May Result....Gap on the A/C Iridium Plugs is Gaped to 1.01mm (0.040 inches).....

 

According to me, Iridium Spark Plugs for 5.3L Engine is good. It provides fuel better efficiency and smooth, more power. NGK TR5IX # 7397 Iridium Spark Plugs has excellent features like super anti-fouling, superior ignitability, and excellent throttle response to your 5.3L engine. I give amazing consistent stability and durability.

 

x-5 on the Iridium plugs.

But as for the gap on Iridium plugs, I find the vast majority 75%+ are not at the .040 gap as claimed. Stick a wire gauge and see for yourself. Allow a 0 to .003 tolerance of the .040 gap on clearances when measuring. There is no such thing as a "pre gapped" spark plug when AC kicks out over a couple hundred thousand an hour in production.

I'm one of the very few that still has the gauge fixture for 14mm plugs to get them at the designated gap. I got so tired of the "pre gap" statement from techs, then I go in and re-gap these plugs to cure a roughness issue. It same belief of slamming a crank and rods and not checking clearances. Your an idiot if you don't check rod and crank bearings as well as spark plug clearances.

 

I also use AC Delco iridium plugs and the box does say they are pre gapped. The box also cautioned that re-gapping can damage the plugs. But like Rick says I checked the gap and found a couple to be off a bit. I had no problem re-gapping them.

 

Can I put ac delco iridium spark plugs on a 2002 Chevrolet avalanche with a 5.3? And what is the part number?

 

It is the physical skill set in making the gap adjustment. Learn after 48 years in what not to do.

 

Doesn't matter, just check the gap
if it's ok - you are good to go

I'm using NGK Iridium now (7397 TR5IX Iridium IX Spark Plug), but had an experience with Champion and they were awful.In winter I coudln't start an engine

 

if you google "best spark plugs for sierra" you will find a dedicated guide which I've wrote


You are welcome
If you have a feedback about my review — you are welcome. Text me here on in private messages

 

Liam, your review appears to be opinion and perhaps personal choices.
I agree with your #1 and your #2 choices; but I have nothing but gut feelings and personal preference to go by.

To rate those plugs as you have rated them requires rigid testing and the publishing of the results.
The results will allow you to rate the plugs in a constant state of environment.
Do you have these tests and the results to backup your choices?

 

To rate those plugs as you have rated them requires rigid testing and the publishing of the results.

I'm thinking about this. It's quite labor-intensive work, but I believe that it might help to rise trust to my reviews

What would you like to see in those tests? What is the ideal review look like?

 

It is labor intensive, but you can't make claims that one is better than the other without documented proof.

You need to devise tests that will backup your claims, actual performance results.
chart the results and list in the order of good to best.

 

Yes, with tests it might change

My it's my personal opinion, my personal TOP which I made out of my experience and users reviews

I'm thinking about performing test
Can you share the chart examples? What would you like to see in them?

 

This is funny (coincidence), last night I watched a show on Motor Trend where they compared the stock AC Delco plugs on a 5.3L with the E-3 ones. On a dyno they ran 2 pulls with each and averaged HP & Torque. The E-3s gained somewhere around 5 - 7 in both. The E3-s used a little more fuel but, with the gain in HP they said you'd get better mileage too I was under the impression that they were just a gimmick but, I guess not, ha ha.

 

I've never tried the E3s, the price (at least in Canada) always chased me away.

But, keep one thing in mind, E3 is a paying sponsor of those shows

 

keep one thing in mind, E3 is a paying sponsor of those shows

That may be but, I would hope they're not fudging dyno results, LOL.

 

E3 spark plugs are with many users that had ,,,,,,,,,,,,,,, engine problems ...

 

I used Project farm for things like this. Many on the ones mentioned here was included on this review. This doesn’t take into consideration for the GMC engine, but here it is if anyone is interested.

 

engines have the spec's on various engines .... use the OEM correct spark plug ... manufacturers did change the spark plug spec's... on my 2000 5.3L engine .. GM changed the spec later ,,, to my install 0n the iridium plugs LOL...
you have a project farm ?

 

AC DELCO IRIDIUM SPARK PLUG .040 5.3L ENGINES

 

The ACDelco Platinum plugs have been fine here in cold Alaska.
I'm using them now in my Gen III 5.3L right now, and probably have 75,000 miles on them.
I'll replace them this summer.

 

AC DELCO IRIDIUM SPARK PLUG .040 5.3L ENGINES 100K miles.
Platinum plugs 40K miles.

 

Yes 41-132