I have a 2003 Tahoe with the 5.3 Flex Fuel engine with 85.000 miles on it. I am planning a 2000 mile round trip vacation drive and was toying with the idea of changing spark plugs. I know the current thinking is that the plugs are good for 100,000+ miles, and I don't doubt that it will run that long, but I thought if I could maybe pick up a mile to the gallon and do my part to reduce my carbon footprint (lol), it might be worth the $8 each price. Any opinions?

I have a 2003 Tahoe with the 5.3 Flex Fuel engine with 85.000 miles on it. I am planning a 2000 mile round trip vacation drive and was toying with the idea of changing spark plugs. I know the current thinking is that the plugs are good for 100,000+ miles, and I don't doubt that it will run that long, but I thought if I could maybe pick up a mile to the gallon and do my part to reduce my carbon footprint (lol), it might be worth the $8 each price. Any opinions?

If these are the original plugs, they should be at least removed and re-installed to prevent the plugs from seizing in the engine.

It won't hurt much to replace them. The only hurt is the $64+tx.

Apply a never-seize to the threads when replacing the plugs.

Plug gap is 0.060 inch.

I have a 2003 Tahoe with the 5.3 Flex Fuel engine with 85.000 miles on it. I am planning a 2000 mile round trip vacation drive and was toying with the idea of changing spark plugs. I know the current thinking is that the plugs are good for 100,000+ miles, and I don't doubt that it will run that long, but I thought if I could maybe pick up a mile to the gallon and do my part to reduce my carbon footprint (lol), it might be worth the $8 each price. Any opinions?

the plugs are at best good for 50,ooomi...the irridium a/c plugs are recommended..,,,,as the plug tips on these engines will get hotter than other engines and the platinum gets vaporized,,,resulting in a poor spark...when replacing always use dielectric grease on plug boots and measure plug wire resistance,,,should be around 650 OHMS..

checking plug gap must be done with care so as to not damage the fragile plug tips....

Thanks guys. I'll just replace them, I wanted to anyway, just guess I needed some convincing that I should.