In the quest to increase fuel economy an issue that always comes up is motor oil. And rightfully so. Motor oil is the lifeblood of the vehicle. It lubricates engine components and reduces friction between metal to metal contact within the motor. Theoretically the better an oil can decrease friction the more horsepower it will free in the motor and the better the fuel economy that will result. This is quite true and some motor oils are better than others. But in the quest to increase gas mileage here are some rules to live by.
1. If you are using a high viscosity (thick) motor oil such as a 10W-40 and your vehicle calls for a 5W-30, switch to the lower viscosity 5W-30! This simple task can increase your miles per gallon by 1% or 2%.
2. Switch to a synthetic motor oil of the correct low viscosity your car calls for. Synthetic motor oils have oil molecules of a small uniform size as compared with those of regular non-synthetic oils. This decreases friction and improves fuel economy. Synthetic motor oils vary but some companies claim gains of up to 5% in fuel economy just by switching your stock motor oil to their synthetic brand.
3. Change your oil within regularly scheduled intervals. More so than improve your mileage this will keep built up oil sludge from oxidation from decreasing the effectiveness of your motor oil. It is a good precaution to keep the oil flowing properly and protecting your motor from excessive damage to other components as well.
Our personal experience is by no means an endorsement of a particular brand of synthetic motor oil. We are just recounting our experience as it occurred and how it helped us improve our fuel mileage for your benefit. As accounts range on how different motor oil products on the market affect gas mileage you should do your own research to determine the most effective one for you. Here is our experience:
As was mentioned in the restore stock performance section, we had finished replacing gaskets and other components bringing the fuel economy back to its normal levels. At this point we began exploring other avenues for improving gas mileage. After some research we decided to switch from stock 10W-30 motor oil to Royal Purple 10W-30 synthetic motor oil. At the same time we also decided to try the Royal Purple Synthetic Transmission Fluid as well. I had a transmission shop replace our transmission fluid, but did the oil change myself. Over the next few weeks I continued to log our fuel economy and was pleasantly surprised. My mpg’s increased from around 24.6 on average to slightly over 26 miles per gallon. That is an improvement of 5.7% just by switching to a synthetic motor oil and transmission fluid! We were very happy with this and were not expecting such good results.