An available navigation system tops 2005 additions to Chevrolet's large SUVs. Tahoes are cousins of the GMC Yukon and Yukon Denali; the longer Suburbans are kin to Yukon XL/Denali XL. Tahoes come as half-ton 1500s, Suburbans in 1500 and heavy-duty 2500 models. All offer LS, upscale LT, and off-road-oriented Z71 trim and a liftgate with opening glass; swing-out rear cargo doors are dropped. A 3rd-row bench seat is standard for Suburbans, optional on Tahoes for up to 9-passenger capacity; 2nd-row buckets are available with the LT or Z71 package. Front side airbags are optional. Head-protecting curtain side airbags are unavailable.