AutoliteIridium XP Automotive Replacement Spark Plugs, XP5245 (4 Pack)

In my decision on buying some spark plugs for a tune-up on my avalanche I needed a trust worthy plug that would stand the test of time,I had bought some bosch plugs but one of the plugs died on me when driving less than ten miles(high way)I don't know if this plug was dropped before I bought it but I ended up removing all of them and going with these from autolite.very small power gain and just a good idle is what you will expect from these,You need to make sure to gap these (unlike the bosch plugs that are already gapped from the factory)these had like a .065 gap when my engine calls for a .040(so don't forget to gap them).As far as durability I would say after five hundred miles their as good as the day I put them in(but I will write back if there is any change in performance)I've used denso,bosch,ac delco and champion in the past so I thought I would try autolite this time.the denso spark plugs worked for the most part just as good as the rest of them with the exception of why I had to change them(one sparg plugs tip had completely disappeared)so for the most part in my thirty years of tune-ups I've only had two brands fail on me in a stock(not modified engine)those were bosch and denso(which happen to be some of the better brands out there)I only recommend things when I have tried them out for a long time so at this time I can only say that I am happy with the performance and fuel economy and also the price of the autolites(the truck I own has one hundred thousand miles on it and runs smoother than a babies but)so if this gives you any idea as to how they work then there you go.

I probably only have a few thousand miles on them but they are working great. I have a 2009 canyon I did a v8 swap on (pulled a 4.8 from a 2012 chevy express) I did gap these to the max allowance from the autolite website. I also run HPTuner software and the outcome what mostly good. These plugs did not change my spark table in the least so for factory swap out these are great. However, I was hoping to see SOMETHING on the power side, hence way I gapped them, and it was exactly the same. So depending on what you are trying to do that is my personal results.A side note, the ground electrode looks like it is more clipped on vs welded or other means. I was nervous at first thinking it could break off in the motor especially if I was bending on it to change the gap. The factory plugs I ordered by the part number for the initial swap looked exactly the same. I had no issues with those and I have no issues with these. I no longer anticipate issues either.

You only get one spark plug for the price you pay. Or at least that’s what was communicated to me when it was delivered and it was only one plug in the box.

I am just a do-it-your-self car owner and not an expert on performance. Not sure how to evaluate this spark-plug. They work as expected. Got then on sale and with an additional mail in rebate, so for the price, this XP5245 was my best choice.They came with a big gap like .060 and I could not find a good source of technical data on the proper gap to achieve the best performance.There are many sites that recommend some gap value but the problem is that they don’t all agree. For my 2007 Yukon XL with 5.3L flex engine I found recommendations that range from .028 to .044 and even sites that say not to gap the original .060 set on Iridium sparks by manufacturer. The original sparks I removed from the car were ACDelco and their gap were like .030 and I had 110,000 miles on them by this December 2012. So I ended up gapping them at .040.Now it seem that my fuel economy has dropped. I went on a Christmas trip to a relative's place about 600 miles round trip. I have made this trip many times in the past and my Yukon was giving me 17.5 to 18 MPG consistently. This time I only got 16.1 MPG.An almost 10% less efficient. I don’t know what else could have changed (speed, tire pressure, weight, weather, gas pump accuracy, etc) but I feel everything was within my norms. I would have to remove the plugs, re-gap them to something else and re tests to see if the MPG would change. But couples of plugs were hard to get to so not sure if I want to go thru this effort any time soon.

Excellent Seller, Package Well, Just as Described, Would Buy from Again!!!

described.

Seller did not have the quantity that I ordered so they asked me to send the items back and they refunded me in full.

Listed as a 4-pack, I only received one. The one I received was the correct type, but I didn't realize I'd only received one until it was too late to dispute the order. That's what I get for not opening the package until I had all the parts for the car is was working on.