Not sure if this is the right threading about the gas consumption on my 2007 prius. It was doing fine all the yearswith my average of 45mpg on hwy and 43 on city and side street. Presently 146k mileage, using 5w-30 quaker state synthetic oil, consuming 1/2 of a quart every 4,500 miles which is my change oil. I been up to date on all my filters, air cleaner, change oil both transmission and engine, tire pressure 38F/36R. All I did last 2 months ago was change oil weight 10w-30 (previously 5w-30) same quaker state synthetic oil. Now my car is down to 38.9 mpg on city/street miles. Is this really possible? Any infor would be great. Thanks, CCG
no, this is the 2012-2015 plug in prius forum. you would want to post here, in the gen 2 (2004-2010) fuel economy forum: gen-2-prius-fuel-economy.21 idk if heavier oil could cause that, but maybe switch back and see what happens. other than that, there are so many things that could cause it
