This week on The Best of Car Talk, Cynthia is so convinced her gas mileage improves when she gets her oil changed, she bet her boss 100 bucks. If she can't win on technical grounds, might Tommy the Philosopher King be able to bail her out? Elsewhere, Linda may be on firmer scientific footing by claiming her husband's "wah-wah" pedal driving style is doing more harm than good. Also, Joyce's hood won't open, and given the overall condition of her car, an air chisel might be the right tool; Scott is looking for eco-friendly windshield washer fluid, and on Stump the Chumps, we find out if Tom and Ray helped Laurie's Pathfinder lose its nickname, "Wobble Butt". All this and more, this week on The Best of Car Talk.