I have a running bet with a coworker that changing oil does not improve gas mileage but i can’t seem to find a source to prove of disprove this fact, anybody know anything about this?
There are two ways in which an oil change could affect gas mileage, both of which result from going too long between changes. Very old oil can increase in viscosity which creates greater drag within the engine. It would take more fuel to overcome the extra drag. If you always go too long between changes, your engine will wear out prematurely and use extra fuel because it no longer runs well. If you change your oil on the recommended schedule, the old oil will still be pretty good and gas mileage should not change.
One other way is if you live in an extremely cold climate, like North Dakota or Minnesota in the winter. Your owner’s manual will likely specify a thinner base weight oil in the cold weather. In -20 degree F weather that definitely makes a difference.
Possible, but not likely for most drivers.
Co-workers always know a lot about cars. The guys used to ask 25 people what they thought was wrong with a car and there were 25 different answers. In the low tech days I would tell them to take it to Jones a mile away and let him worry about what would fix it. Quit talking and drive happy. In your case. be a politician and don’t get into discussions with obviously uninformed people with dubious knowledge. They’re always right and can’t be swayed.
Right. Why get 25 different answers when you can post here and get 50 different answers.