Gas costs are risk to GM rebound.

General Motors Corp. is off to a good start with its new lineup of large SUVs, but rising gas prices could pose a threat to sales of the fuel-thirsty vehicles and sap momentum from a key piece of the automaker's turnaround efforts. Gas prices, now at close to $3 per gallon, have not yet dampened demand of the new Chevrolet Tahoe, GMC Yukon and Cadillac Escalade. Hot sales of the profitable SUVs were one of the bright spots of GM's first quarter financial results, released Thursday.