Diesel starring Harish Kalyan in the lead releases in theaters worldwide on October 17, 2025, and is one of the three Tamil movies out to entertain this Diwali 2025 weekend. Diesel stars Harish Kalyan in a rugged, mass-action avatar, and the movie is written and directed by Shanmugam Muthusamy. Here are 5 reasons to watch Diesel in theaters this holiday season:  

1. Story: A Forgotten Chapter of India’s Oil Smuggling Past

Set against the backdrop of India’s underground oil mafia, the film Diesel explores how loyalty and revenge collide in a world built on 'Black Gold' i.e. crude oil. Diesel takes us back to a time when crude oil was illegally smuggled through underground pipelines from ports like Chennai, Mangalore, Gujarat, and Mumbai.

A secret network of criminals profited from this billion-rupee trade, until technology and surveillance gradually brought it to an end. Set across multiple years and wrapping up around 2014, Diesel captures the rise and fall of this black-market empire. 

2. Harish Kalyan’s First-Ever Diwali Release

After delivering two back to back hit movies in Lubber Pandhu (2024) and the National award winning Parking (2023), for the first time in his career, actor Harish Kalyan headlines a big festive release. Shedding his romantic-boy image, the actor steps into the role of a smuggler caught between crime, morality, and justice.

The film Diesel marks a major transformation for Harish — both in tone and in scale — as he takes on his most intense and mature role yet.

3. Realistic Action and a Coastal Backdrop

Unlike typical urban thrillers, Diesel unfolds around fishing harbours, portside towns, and coastal smuggling routes, giving the film a distinct visual identity. Expect realistic action sequences, tense confrontations, and emotionally charged drama, all amplified by raw cinematography and a thumping score. The film’s scale feels theatrical — designed to pull audiences deep into the underworld it portrays.

4. Diesel Cast and Crew

Diesel is Harish Kalyan's most expensive film yet, and true to its budget the movie comes with a big ensemble including names like Vinay Rai, Athulya Ravi, P. Sai Kumar, Ananya, Karunas, Ramesh Thilak, Kaali Venkat, Vivek Prasanna, Sachin Khedekar, Sai Krishna, Zakir Hussain, Ravi Venkatraman, Thangadurai, KPY Dheena, Apoorva Singh, L.Devadharshan, Satheeshan Kanjikuzhi. 

Dhibu Ninan Thomas has composed music for Diesel, and the viral Beer Song from the album has already brought significant attention on the movie. 

5. A Long-Awaited Debut, Runtime

Debut directors in Tamil Cinema have off late given promising content, and Diesel is from a filmmaker who has long awaited his debut. After his earlier unreleased projects (Puranagaram, Agangathey), Shanmugam Muthusamy finally makes his feature debut with Diesel.

An U/A censored movie, Diesel comes with a runtime of 2 hours 44 minutes 35 seconds, which is right inbetween the other two Diwali releases this Friday.