Get extreme Fue:

48992519 - Camo (Helmet)
20061977 - Road Addict (Jacket)
91031985 - Speed Angel (Trousers)
17121973 - Flash Mudhog (Paint)
18021974 - Moto Sludgeray (Paint)
18041851 - Warrior (Vehicle)

Go to the folder: "Codemasters\FUEL\GameTsc\Story" and find the file "hubinfos.tsc" and open it with notepad.
Here you can change the amount of fuel you gain after you pass a certain level.

For example, for "YellowStone:"

Change AddMissionFuel "CR1-Yell-CP" 440 440 440"
To AddMissionFuel "CR1-Yell-CP" 99999999 99999999 9999999

Change that same value to "9999999" for each level.
After you pass a level whih you changed it's value you will be awarded with awesome amount of fuel and you can buy any Vehicle that you like!
Sent in by: p30sky

Complete each achievement to get the allotted gamerscore. If you have an Xbox 360 gamertag, you can log in using this same gamertag and the achievements will count the same as if you were playing the 360 version.

Unlockables

'Tis but a scratch! (30) Finish a career race ranked 1st without wrecking your ride.
A prophet in his own country (15) Finish ranked 1st on 10 online custom races you HAVE created.
A stroll in the park (15) Drive a cumulative total of 62 mi (100 km) in free ride mode.
All your camps are belong to us (30) Unlock all 19 camps for great justice!
Black gold tycoon (15) Collect 500 oil drums on the field.
Blind man's buff (15) Finish a career race ranked 1st without GPS.
Born under a lucky star (15) Win your first Star in career mode.
Completion obsession syndrome (40) Now, go breathe some fresh air!
DIY (15) Create a race using the race editor.
Gear buff (15) Own 48 pieces of gear for the driver in career mode.
Gear freak (30) Own 72 pieces of gear for the driver in career mode.
Gear lover (15) Own 24 pieces of gear for the driver in career mode.
Globetrotter (30) Drive a cumulative total of 620 mi (1000 km) in free ride mode.
Hello, world! (15) In free ride, go from Offshore Shack Camp to Tsunami Reef Camp without resorting to the chopper.
Here comes a new challenger! (15) Win a challenge.
Hobbyist challenger (15) Win 30 challenges.
Hobbyist collector (15) Own 10 vehicles.
Hobbyist painter (15) Collect 50 vehicle liveries.
Hobbyist sightseer (15) Find and contemplate 10 Vista Points.
Hobbyist stargazer (15) Win 40 Stars in career mode.
Humble beginnings (15) Win all three Stars on ‘Riders on the Storm’.
Natural selection (15) Finish 30 online Career races ranked 1st.
Newton was right, after all (15) Fall 150 meters
Obsessional challenger (90) Win all 190 challenges.
Obsessional collector (30) Own all 74 vehicles.
Obsessional painter (30) Collect 148 vehicle liveries.
Obsessional sightseer (30) Find and contemplate all 95 Vista Points.
Obsessional stargazer (90) Win all 216 Stars in career mode.
Oil rig (15) Collect 100 oil drums on the field.
Oil strike (15) Collect your first oil drum.
One of each, please! (15) Own at least one vehicle of each type.
Open your eyes (15) Find and contemplate a Vista Point.
Path to glory (15) Win all three Stars on ‘Twisted Minds’.
Regular challenger (30) Win 100 challenges.
Regular collector (15) Own 40 vehicles.
Regular painter (15) Collect 100 vehicle liveries.
Regular sightseer (15) Find and contemplate 50 Vista Points.
Regular stargazer (30) Win 120 Stars in career mode.
Rocket science (15) Travel 80 meters in a single jump.
Safari adept (15) Drive a cumulative total of 310 mi (500 km) in free ride mode.
Salt over Snow (15) In free ride, go from White Flats Camp to Pinwheels Ridge Camp without resorting to the chopper.
Sand to Stone (15) In free ride, go from Tsunami Reef Camp to Redrock Bluffs Camp without resorting to the chopper.
Squadala, we're off! (15) Use heliports 100 times. Faster than a flying carpet, huh?
Under the limelight (15) Win all three Stars on ‘All’s Well That Ends Well’.
Underground brotherhood (15) Play and win 30 online custom races you haven't created.
Wriggling about (15) Perform 200 tricks (bikes and quads).