In reading messages I've noticed that people are experimenting with different engine oils, tires and tire pressures. My recommendation is to stick to Honda's 0-20W oil (2.6 quarts w/filter change) and factory spec tires with 38 psi front, 35 psi rear tire pressures. Honda's engineers are top-notch and have defined these specifications for a reason. The Insight was designed from the ground up as a total package in which all of their specifications work together for best performance and reliability. Unless you are well-connected with Honda's engineering staff, I would not advise experimentation outside of their recommendations. The likelyhood is great that you will negatively impact some aspect of the Insight's performance and/or reliability. This is just my opinion. Happy motoring!