I've got an 04' Rodeo with 3.5ltr only has 75,000mi. I have to add at least 2qrts of oil every 2000mi. No smell of buring oil or sign of leaking. Gas mileage is also poor. Any ideas what might be the cause of this?

 

possible head or manifold gasket tear. check and see what your coolant looks like, it it looks anything other than clear and green then i might be concerned.