Should I get a tune up at 105,000 miles? Is it necessary? I'm at 104,000 and I'm getting better mileage now than ever. Today I got 110.4 MPG on a 17 mile stretch where my previous high was 105.9. Been getting 80 MPG, or just under 80 going to work. If it's not necessary to get a tune up now, what conditions should I look for that will tell me it's time?