When considering the most significant engine of all time, the debate often gravitates toward groundbreaking designs that have significantly influenced automotive history. The Ford Model T's inline-four engine emerges as a prominent contender in this context. Introduced in 1908, this engine's simplicity, reliability, and affordability played a pivotal role in democratizing automobile ownership, marking a turning point in both automotive and social history. Its design was so effective that it remained largely unchanged for nearly two decades, a testament to its efficiency and durability. The Model T engine's legacy is not just in its technical specifications but in its broader impact on society, setting the foundation for mass automobile production and changing the landscape of personal transportation.

When evaluating different car companies and their models, it's crucial to recognize the diversity and specialization in the automotive industry. However, if one were to single out a specific model for its engine's excellence, the Mercedes-Benz 300 SL's inline-six would be a compelling choice. Introduced in the 1950s, this engine was ahead of its time, featuring direct fuel injection - a first for a production car. This innovation significantly enhanced performance and efficiency, setting new standards for high-performance engines. The 300 SL's engine not only powered one of the most iconic sports cars of the 20th century but also influenced future engine designs, making it a benchmark in automotive engineering. Its blend of innovation, performance, and historical significance positions it as a strong contender for the greatest engine of all time.

Question: "Greatest Engine of All Time" I chose for the Discussion Paragraph. Based on this, Look up engine parameters (hp, rpm, displacement, fuel properties, etc) for it, and solve for the actual engine thermal efficiency (assuming a volumetric efficiency of 90%). Also, solve for the temperature, in degrees Celsius, at the end of the compression stroke.