My 2006 is @ 2850 miles. I filled up the same way, same station, same gas, same weather conditions. The only variable is I ran the A/C 3 days this week as we're in early summer. Computer said: 50.9 MPG/ 275 miles. Pen & pad said: 55.7 MPG/275 miles. That's also with the trim rings parked in my closet for E bay someday. At 5,000 miles I'll put in the Mobil 1 and hopefully with less friction get even more MPG.
I heard that it would be better to wait on going to synthetic oil until 10 or 15k miles so the engine has time to break in and the rings get a good seal.
I've read (on this board) that this is no longer true on any modern cars; you can go to synthetic right away with no adverse consequences.
Here is a link read the section "precautions when using synthetic oil" # 1 http://www.utextension.utk.edu/publication...les/SP268-Q.pdf It says " auto engines should have at least 6000 miles before the change over".
This topic has come up again and again in this forum, and likely will for some time. The simple rebuttal to anything that states that you should wait until your car hits 6k, 10k, or 15k miles to switch over to synthetic so that the engine can properly seal is that a number of cars come factory direct filled with synthetic oil: Aston Martin, Bentley Amage and Bentley GT, Cadillac CTS, XLR, SRX and STS, Chevrolet Corvette, Dodge Viper, Mercedes-Benz AMG and SLR, Mitsubishi EVO, Pontiac GTO, and all Porsche vehicles - and these are just the ones that come filled with Mobil One. I switched over to Mobil One at 4,000 miles, and have experienced no ill effects now through my current mileage of 26k. Modern engines have much more precise specifications than those of years past, so the need for a traditional oil break-in period is customary at best.
I can get an extra five MPG's by taking the lead out. Of my foot that is. Nothing absolutely nothing improves Prius gas mileage more than driver re-education. You can zip around like a sports car and get 30 MPG or you can get ready for century 21, no not the real estate sellers, and learn to drive efficiently. There are more tips avail on Priuschat on how to drive a Prius than there are molecoles in 3 oz of acetone.
Yes, I'm impressed. Priuses love it warm. Looks like I have a few more months before seeing those numbers.
