OK guys, so recently i've been filling up alot more than normal. no extra driving i have fairly new spark plugs, clean air filter, and properly inflated tires. the only thing i can think of is when changing my oil recently i accidently grabbed 5w 20 instead of the normal 5w 30. but when reading up on oils on the net and the fozz's owner manual i got contradicting info. the manual says lower viscosity= better MPG and several websites said the opposite. is my mistake in oil weight causing this drop in mpgs? like i said its the only thing that's changed. any answers would be greatly appreciated.