If I switch from conventional oils (10W-30) to Mobil Extended Performance (5w30), what performance changes might I expect? Oil pressure, RPM, gas mileage? I have a 1995 Chevrolet C1500 5.7L at 274,000 miles. Thanks
-- Richard Clarke, Katy, TX
Answer:
It is difficult to answer this question without knowing more about your vehicle. Has it been maintained properly, and does it still provide good control of oil consumption? In what kind of service is the vehicle used? Has the engine been modified or been rebuilt? Are there any external leaks? If I assume the engine has been well maintained, has not been modified or rebuilt, and does not have any external leaks,then I would say switching to a 5w30 from 10w30 may yield some fuel economy benefits over the long haul. In other words, do not expect a huge improvement in fuel economy over your first few tankfuls.I would also not be surprised that at least initially you experience an increase in oil usage for a few changes. This is normal and occurs when you change the brand or type of oil you are using. This would be especially true since you are changing viscosity grades. I would also expect your oil pressure to be lower and your RPM may be a little higher. If your vehicle is used in tough service or experiencing the signs of age, you may want to consider using a higher viscosity oil or an oil specifically designed for higher mileage vehicles like new Mobil 1 High Mileage 10w30 or 10W-40.
-- Richard Clarke, Katy, TX
Answer:
It is difficult to answer this question without knowing more about your vehicle. Has it been maintained properly, and does it still provide good control of oil consumption? In what kind of service is the vehicle used? Has the engine been modified or been rebuilt? Are there any external leaks? If I assume the engine has been well maintained, has not been modified or rebuilt, and does not have any external leaks,then I would say switching to a 5w30 from 10w30 may yield some fuel economy benefits over the long haul. In other words, do not expect a huge improvement in fuel economy over your first few tankfuls.I would also not be surprised that at least initially you experience an increase in oil usage for a few changes. This is normal and occurs when you change the brand or type of oil you are using. This would be especially true since you are changing viscosity grades. I would also expect your oil pressure to be lower and your RPM may be a little higher. If your vehicle is used in tough service or experiencing the signs of age, you may want to consider using a higher viscosity oil or an oil specifically designed for higher mileage vehicles like new Mobil 1 High Mileage 10w30 or 10W-40.
