The Chevrolet Colorado and GMC Canyon will soon be offered with a 2.8-liter Duramax turbodiesel engine but that hasn't convinced Toyota of the need to offer a diesel engine in the redesigned Tacoma.

Speaking during a live chat, Tacoma chief engineer Mike Sweers confirmed the truck wouldn't be offered with a diesel engine. He went on to say "We’ve looked at diesels" but it's a "difficult topic right now because of the new Tier 3 emission regulations.”

Sweers went on to say a diesel engine could improve fuel efficiency by about 30 percent but it would require an after-treatment system which would add up to $3,000 to the price of the truck. The engineer went on to say the math simply doesn't work out especially when you consider that diesel costs about a dollar more a gallon than petrol in the United States.