Just returned from 3580 road trip. From Temecula.Ca through Nevada.Idaho to Big Fork, MT. to Seatle. WA. then home. Various road conditions and weather, speeds at or above posted limits. Average MPG 29.56, high 33.62, low 27.29. 2003 MCS with MINI-MADNESS AIR INTAKE. Just though someone would be interested.

 

>>Just returned from 3580 road trip. From Temecula.Ca through Nevada.Idaho to Big Fork, MT. to Seatle. WA. then home. Various road conditions and weather, speeds at or above posted limits. Average MPG 29.56, high 33.62, low 27.29. 2003 MCS with MINI-MADNESS AIR INTAKE. Just though someone would be interested.

Aloha and welcome to MCO-daniele625
Thanks for posting the mpg info. How did you calculate it? If you used the trip computer then the numbers may not be accurate. The best calculations are done manually by filling up the tank at the same gas station with the same pump in the same way and then driving then refilling after 100 to 300 miles. On a trip cross country there are many different pumps and the levels of filling each time can be different.

In Hawaii with my MCS I can get 35 mpg on the freeway and 28 in mixed city and hwy driving. 2003 MCS with 4800 miles. AC always off. Premium gas only. Hwy speed up to 65. Madness intake and quicksilver exhaust. No cruise control and no trip computer on my car.

 

The old faswhion way. Fill tank until it won't take anymore, divide tolal gallon into mileage from the trip meter on the odormeter.
ps. speed between fill-ups are were at least 10 to 15 miles per hr. higher than what you are doing in Hawaii