1999 Hummer Model Year Changes.
|1999 saw some significant changes for the Hummer. Government regulations required the Hummer (which is a class III Truck) to have ABS for the first time. Unfortunately the Torsen differentials and the Brake/Throttle Modulation (BTM) Technique that made them so effective off-road were not compatible with the required Anti-lock Braking System. The solution to keeping the Hummer's Off-road prowess and complying with the regulations was Torque Trac 4 or TT4. This electronic system preforms a version of BTM but without driver participation. When wheel spin is detected, brake is automatically applied to the spinning wheel and torque is transferred to the wheel with traction. The new Torsen II differential works much the same as the old Torsen but with less torque bias. Manual BTM still works on the '99 Hummers but is not as effective because of the lower torque bias. Some owners love the TT4 system while others prefer the old system of manual BTM .|
Powertrain and Identification Information.
|Significant changes for 1999.
|Valuable upgrades to look for in a '99.
|'99 Specifications, options & Prices:|
|Mesa Dusk (C22). New Color for '99.||Night Storm (B21). New Color for '99|
|Competition Yellow (Y20).|
|Candy Apple Red (R19).|
|Silver Metallic. (S15)||White. (W8)|
|Black. (B9)||Bright White. (W14)|
|Although most factory custom colors show up on emergency vehicles and as factory tests, custom colors were available on all Hummers for an additional $1,000 charge. Below is an example of a Hummer with a factory experimental color (X), Cactus Green. Cactus Green never made it into full production.|
|Body Styles Available in '99:|
|HMC4. 4-Passenger Hard Top. VIN 6th & 7th Digits "83"|
|HMCS. 4-Passenger Wagon. VIN 6th & 7th Digits "84"|
|XLC2. 2-Passenger Hard Top Enlarged Cab. VIN 6th & 7th Digits "89"|
|HMCO. 4-Passenger Full Door Open Top. VIN 6th & 7th Digits "90"|
TOTAL PRODUCTION COUNT BY MODEL AND COLOR. "X" Colors are "Experimental" or special order, often seen as production colors in later years.
2505 Highway K
O'Fallon, MO 63368
P: (636)777-7600 Adventure Accessories