Maybe I can see if I can get one of the Moroso guys up here to answer some questions if that helps whom ever. even if its about oiling or even cool stuff they have done for race teams.

I think that would be cool for the site and all of us.

I agree with Griff about the heat issue but the abrasion protection if a definite plus.
I’m in for a couple sets when they’re available.

Just adding some thoughts as how I am looking at this and the reasons why - IMO the sleeving makes the wires look better and the colors seem more vibrant plus will not dull over time. Next my thoughts are -- how many boaters have really overheated their marines engines ? I see this a lot especially with mainstream boat owners - or how many sucked up a bunch of crap from the waters and one tube or more of CMI headers is running super hot ? Or even plugged up a sea strainer to cause an over heat ? Comparing to the auto side - I can not even remember the last time I seen an overheated car on the side of the road and we prob have 2 million autos running around here everyday 7 days a week.

Next is all electronics hate heat - when you add heat its causes electronic resistance - that in return causes increase in OHMs thru wires and circuits and sensors and so on - the sleeving keeps the wires cooler at all times to help with that.

Keep in mind 40 ohms per ft wires and I am working on even lower OHMs for wires. Also rubber degrades from heat over time as any increase temps from whatever heat source will dry out the compounds.. The sleeves will only add longevity to the wires.

The marine engines with cat exhaust run at 800 degrees around the cat and air space within the exhaust / risers - it has to build that amount of heat to operate correctly. When the impeller sheds - trust me the wires can blister. This is another reason why I am testing against heat.

When you see wires like this - These have been way over due. Volvo wires suffer at the boots to cap and start down the wire itself. Just like old tires that UV caused the degrading of rubber and the brownish discolor. everyone has seen that with boat trailer tires down the road. ( the brown discoloring on the walls of the tires ). The same with Volvo wires..

These wirers and boots were hard as a rock and the engine ran very poor. New cap and rotor and spark plug wires and plugs all good to go ran like a top as it should.. Pic below

and the reason why you OHM test wires but you need to know the specs of the OHMs per ft of the wires you have installed to see if they are within the specs. like I said more volvo wires and boots so common -- pics below and 2 wires were OL, ONLY 309 hours on the engine scan.
. this only had 309 hours on it

Thanks for the answers and pics

Amongst other things, Big plug gaps kill ignition parts. Right 496 owners ?