In 1975, AMC engineers embarked on a journey to enhancement, elevating the displacement of the 232 CID engine to 258 CID. This evolution saw both iterations, the 232 and the upgraded 258, coexisting in the automotive market. Initially, the 232 served as the base engine, while the 258 emerged as the preferred upgrade. However, as time progressed, the tables turned, and the 258 assuming the mantle of the base option, leading to the eventually discontinuation of the 232.
In 1987, with the reintroduction of the I6 engine as a formidable 4.0L (242 CID) powerhouse, featuring port injection technology. This reincarnation found its home in the Jeep Cherokee (XJ), Comanche (MJ, and Wagoneer lineups, alongside its carbureted predecessor, the 258. Notably, the 258 engine found a place of honor in the Jeep Wrangler (YJ) from 1987 to 1990.
The swansong of the I6 4.0L engine unfolded in the Jeep Wrangler (TJ), where the 4.0Lengine reached its zenith before bidding farewell. Throughout its illustrious tenure, the 4.0L engine garnered praise and admiration, earning the accolade of being a “flat-out kick-ass engine” from MotorTrend.com. Its reputation as one of the most reliable and robust platforms for both off-road adventures and urban escapades endures as a testament to its enduring legacy.
From its humble beginnings the Rambler American to its triumphant reign in the Jeep Wrangler (TJ) the I6 engine embodied the spirt of adventure and reliability, captivating enthusiasts with its unmatched performance. As the curtain falls on its remarkable journey, the 4.0L engine leaves an indelible mark on the automotive landscape, a testament to the ingenuity and craftsmanship of AMC engineers.
