Gas mileage for 1999 ford expedition. . . los angeles; sema; pebble beach concours; BLOG; TRAFFIC; GAS PRICES; INSURANCE. Pros: Safety was my #1 concern and this vehicle is very safe. . . . . Email with . . Answered by your About. . . the dealer and upgrading the computer can help gas mileage. Handles great, turn radius is amazing for the size of the vehicle. Best Answer: Here is a side-by-side comparison of the two vehicles you're considering (using a 1999 Tahoe 2-Door 2WD vs. . Toss in gas m... more