I usually getting 22-24 mpg at 65-70 on hwy trips, and 17-18 around town. This is on a '97 with 180k miles, and it a very good state of tune. One thing I noticed that helps is increasing the tire pressure. I will put it up to 38-40 psi and the mileage will increase ~5-10%. The trade-off is feeling every bump in the road. Now not all tires are rated for pressures that high, so do not exceed the max pressure on the sidewall. Also, check my following post on fixing a "rough idle", this has made my RL run much smoother and likely increased mileage a bit. Good luck!