Well, with an engine that has kept up on oil changes, I'd argue that worn seals would be a more significant cause of consumption and fuel dilution.
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I tried putting this stuff into my high mileage 2.5, though I have no objective way to determine its efficacy.
Early on in the vehicle's life, when it was on 0w20, it consumed some oil. a few treatments of STP high mileage oil additive seemed to seal up the engine. It does not burn any oil now, so I recommend those high mileage engine treatments/oils.
Keep in mind that 5W30 is also a "CAFE approved" oil..
I will likely keep using 5w30/5w20 due to price and availability at costco, but ideally I would like to move up to 5w40 at least in the summer.