How many miles per gallon should someone expect from a ’68 Ford Shelby GT-500?
The majority of ’68 Shelby GT-500s came equipped with 428ci engines, but some had 427-inch versions. Both of these engines were healthy, and fuel economy was not what they were designed to excel at. With the 428 engines boasting 10.6:1 compression ratios and either a Toploader 4-speed or C6 automatic transmission, the 3,445 lb Shelby could expect to get between 9-11 mpg.
These figures are based on conservative driving styles and the standard rear axle gearing (3.25:1 with the manual transmission, and 3.50:1 with the automatic.) We doubt too many were ever driven conservatively when new, but a restored example should be able to match these fuel economy figures today.