Transmission fluid is as equally important to the transmission as motor oil is to the engine. Transmission fluid effects on gas mileage occur much in the same way as described in the motor oil section, by reducing friction between moving and rotating metal components. Switching to synthetic transmission fluid can further reduce friction in the transmission, increasing the amount of energy that is transferred to the wheels of the vehicle, thus increasing gas mileage. Here are some tips to improve your fuel economy through your transmission and save money in the long run.
1. Switch to a synthetic transmission fluid of the correct grade for your vehicle. Synthetic transmission fluids have molecules of a smaller uniform size as compared with those of regular non-synthetic oils. This decreases friction and improves fuel economy. Synthetic transmission fluids vary but some companies claim gains of up to 1% to 2% in fuel economy just by switching your stock transmission fluid to their synthetic blend.
2. Change your transmission fluid within regularly scheduled intervals. Transmission fluid lasts much longer than motor oil in the vehicle and it is not uncommon for transmission fluid to extend to 100,000 miles by manufacturers’ claims. However, keeping transmission fluid fresh will also extend the life of your transmission and prevent costly transmission breakdown.
3. Most synthetic transmission fluids also reduce the temperature of your operating transmission, an added bonus which can help to increase fuel economy by letting the transmission run more efficiently.
As we mentioned in the motor oil section, we had finished replacing gaskets and other components bringing our fuel economy back to its normal levels. At the same time as switching the motor oil to synthetic we also switched the transmission fluid to Royal Purple Max ATF synthetic transmission fluid. Over the next few weeks we received an improvement of 5.7% in gas mileage. What percentage of this was attributable to the motor oil and to the transmission fluid I cannot say as we changed them at the same time. But another benefit I realized is that the synthetic oils last longer before scheduled service intervals. This helps to offset some of the extra cost in paying for the synthetics which makes them more worth while.