vec <- c("2010 mercedes-benz sl500r", "2010 mercedes-benz e550", "2010 mercedes-benz glk350", "2010 mercedes-benz c300w", "2010 mercedes-benz 300") gsub("(benz\\s+[[:alpha:]]+)\\d\\w*", "\\1", vec)
Standard input is empty
[1] "2010 mercedes-benz sl" "2010 mercedes-benz e" "2010 mercedes-benz glk" [4] "2010 mercedes-benz c" "2010 mercedes-benz 300"