I was absolutely floored at the difference the RedLine MTL made in the Miata transmission. The improvementn was just incredible, it'll downshift into first now at 20MPH. It used to fight me at stoplights!
In fact, all the Redline stuff works great, it's just very expensive. Tossing $90 at a case of oil isn't for the faint of heart.
When I was in college I had a motorcycle that didn't have an oil filter, so I changed the oil a LOT. Weekly. I found that the engine made less mechanical noise on valvoline than other oils at a given weight. That bike had a lot of piston slap, anything to reduce it made life more tolerable.
Now that Synthetics are out, it's clear that the difference between them and regular oil is far larger than the difference between valvoline than junk oil. Just one quart of synthetic mixed into a regular oil change quiets all of my motors (all six of them!) dramatically. I usually buy a few quarts of valvoline synthetic 10w30 and a case of regular valvoline 10w30.
Mobil 1 every 3,000-5,000 miles. Never try Red Line motor oil. Never had good luck with Red Line even with them sponsoring me. Used RL in the trans and it when out twice. Use RL in the rear and replaced posi every 4-6 months (it's a weak point on f-bodies). On factory stuff I can get 12-18 months. Used RL in the power steering unit and in 6 months had to have it rebuilt. Luckily I found out about Lee's enginering. It's been 7 years and still okay. Lee makes their own fluid and it's great!
For both the Prelude and Integra, Mobil 1 10-30W every 3750 miles, and I have to add at least one quart of oil every 1200 miles 'cuz the motors really consume oil when they're in the VTEC range. Maybe I should change my driving style, but I can't help it. When VTEC hits, it just sounds so nice and the power is nice too.
For what it's worth, when I was racing my Datsun, I would usually change the oil about every 3-4 events, unless I was into the engine, in which case I always put new oil in it. I never reused oil, no matter how long before I had replaced it. I don't remember what oil I used, but whatever it was, it was quality. I think I used a variety including Valvoline, Quaker State, Chevron, whatever was on sale at Pep Boys. I never used "reclaimed" oil, that was for my old '57 Chevy: "Fill up the oil and check the gas!" Redondo Beach to Big Bear and back: 6 (?!) qts of oil. Why drain it? There was a constant change of oil anyway.
With the Lexus, I've been using Valvoline 10w-30 and have been having the dealer change it when I have the mileage-requisite servicing done. But no more Lexus-brand air filters!! $52.20 for the filter and $16.00 to change it!!! Ouch! Had I known they would charge that much, I would have looked into getting a K&N sooner.