Greg and Lars are two refurbished covered Lorries. They were restored by renowned technician Mr. Gregory Larson.
Greg and Lars were reconstructed from an old chassis and parts Mr. Gregory Larson discovered in the Sodor Ironworks. They were rebuilt and given a new life helping to shuttle supplies for the Skarloey Railway.
The two Lorries, however, would be well known for their idleness and alarming ineptitude. On one occasion, Greg broke down about 7 feet out of the shed, and backed into a stockpile of crates and a bridge support (which he blames on his "blindness"). On the same day, Lars collided into a Quarry Water Tower, thus leaving Rheneas stranded until an engine could push him home. When the bridge had collapsed, the two Lorries were clever enough to save Sir Handel, but had forgotten that Fearless Freddie was to be expected as well, and unfortunately caused yet another accident.
Greg and Lars conciously skipped work so they could watch the Flying Scotsman arrive with the enthusiasts (which is strange because Greg can't even see).
Lars was present during the Munitions incident.
Greg is misguided, clumsy, and a little grumpy. He believes that he suffers from blindness, but this may be because his sunshades are of a solid black shade. He suffers from engine trouble occasionally and would rather loaf around with Lars than actually be productive. He speaks in a raspy, rugged tone and argues with his brother quite often.
Lars is incredibly lazy but very smart. If he applied himself, he would probably be one of the brightest Lorries on Sodor. His clever plan had saved Sir Handel and his trucks when Greg had accidentally crashed into a bridge support. He would much rather sleep than work. He is also known for his "laid-back" surfer dialect. He often exclaims "Radical!" and "Cowabunga!" as he rolls down the roads. He argues with Greg a lot, but this is mostly due to the latter's controversial "blindness issue".
- Season 1: Lift Bridge (Greg only; cameo), Snow Blind (remastered version cameo), Greg and Lars, Conspiracy Theory (cameo)
- Season 2: Paxton and Norman (Greg only; cameo), Rock-Star, Munitions (Lars only), Swashbuckler (cameo)
- Season 3: Perhaps He's Got a Corset (cameo)
- Greg and Lars are based on Mercedes-Benz LG3000 cargo trucks as seen in the film Raiders of the Lost Ark. Their models in the series are actually LEGO models of these trucks, from LEGO sets based on the aforementioned film.
- Greg and Lars were named after Gregory Larson, the technician who rebuilt them.