Raidin

Hi all,

Been talking to friends of mine who are techs, one being an engineer who used to endurance test parts for GM. Long story short, the engineer has learned that spark plugs, brake fluid, and coolant essentially never need to be replaced. I've already racked up 615k miles on factory brake fluid. Both my friends agree on this point, but not on the spark plugs (didn't bring up the coolant yet).

One says that while they might last a long time, they could cause unburnt fuel to damage the catalytic converters if the plug starts to wear to the point of incomplete combustion from weak spark. The engineer has never replaced cats, longest on a 340k mile Civic on factory plugs I believe, and so doesn't see an issue here. I asked my tech to check cost of the cats. Guess what? They cost $280! From Lexus directly! Cheap as hell considering most tend to cost $1500 to $2000. I checked my Audi's cost as a reference, it was $1990!

So I will run my new Ruthenium plugs until they cause a misfire, and then also my coolant to 200k intervals, and see how things go. I'll keep you guys posted.

JNguyen9

Hi Raidin any updates to this? I have done a lot of reading and it's suggested to replace the coolant every 100k miles. Supposedly the coolant degrades and becomes acidic and could cause the water pump to fail.