theholycow's sig/link meta-thread (Warning: Contains random and miscellaneous stuff)
My sig is full...so I might as well move some of it into a thread and just put in a single link to the thread, right? From now on, I'll add things here and send people here to see them rather than trying to squeeze them into my sig.
Another tire size calculator somewhat like the miata.net one in my sig http://www.roversd1.nl/sd1web/wheelcalc.html
This one has more detail about gear ratios and requires you to enter more data, but calculates more driveline data.
Search junkyards (sorry, "auto salvage yards" (oops, "used auto parts dealers" (I apologize for my political incorrectness, "auto recyclers"))) nationwide for the part you need: http://www.car-part.com
The generally accepted authority for questions, data, and myth-busting about motor oil: http://bobistheoilguy.com
(Keep in mind that it is still a forum and has plenty of people who subscribe to all the myths without an ounce of skepticism.)
More on weight reduction, with actual measured results: http://www.gassavers.org/showthread.php?t=8361
When it's all said and done, some cars can have a measurable FE difference of ~1% MPG per 1% weight change -- so, to get a 10% change in MPG, one would add/remove 230 pounds on a 2300 pound Civic. Other cars may not respond to weight loss at all, such as a 2.5% MPG change resulting from a whopping 19 percent weight change.
Tire size calculator -- tells you the difference in diameter for any two sizes, and calculates speedometer/odometer error (and therefore your fudge factor for figuring your FE): http://miata.net/garage/tirecalc.html