
The model 4A91T is an engine from the Mitsubishi brand. The 4A91T engine originates from Japanese Mitsubishi engine technology and was jointly developed by Shenyang Aerospace and Mitsubishi, entering mass production in 2013. The 4A91T engine is Mitsubishi's latest-generation engine featuring the MIVEC variable valve timing system. On June 26, 2009, the launch ceremony for the Aerospace Mitsubishi 4A9 engine was held in Shenyang. To quickly respond to the trend of downsizing in China's rapidly developing automotive industry and increasingly stringent environmental requirements, Aerospace Mitsubishi, as an important engine production base for Mitsubishi Motors, decided to introduce the 4A9 engine in early 2007 and has since started production in Shenyang. The 4A9 series engine, developed by Mitsubishi in 2004, is produced by Germany's MDC-Power company and is widely used in models such as the Mercedes-Benz Smart, Mitsubishi Colt, and the latest 10th-generation Lancer. As Mitsubishi's core engine in the 1.3L to 1.6L range, it achieves top-level performance in compact size, lightweight design, high performance, low fuel consumption, and environmental performance (meeting Euro 4 standards and also considering Euro 5 compliance). The function of an engine is to convert the thermal energy of gasoline or diesel into mechanical energy by burning and expanding the gas in a sealed cylinder, thereby pushing the piston to perform work. The components of an engine include: the valve train, crankshaft and connecting rod mechanism, ignition system, cooling system, lubrication system, starting system, and fuel supply system. Engine maintenance methods include: using qualified engine oil, using qualified coolant and antifreeze, regularly cleaning radiator scale, regularly removing engine carbon deposits, periodically replacing the vehicle's three filters (air, oil, and fuel), and maintaining reasonable engine speeds.

When I was researching various engines, I specifically looked up information on the 4A91T. It's a turbocharged engine jointly developed by Mitsubishi and Daimler, belonging to the 4A9 series, and is currently mainly used in Soueast Motor's vehicle models. What impressed me most about this 1.5T engine is its aluminum alloy cylinder block design, which is exceptionally lightweight, and its decent fuel consumption control. I've driven my friend's Soueast DX7 equipped with this engine, and its low-end torque performance was quite surprising—the turbo kicks in at just 1500 rpm, making acceleration and overtaking very confident. However, there are a few minor issues to watch out for during later maintenance, such as the turbo pipes being prone to air leaks and the cold start noise being a bit loud. Overall, this engine is considered a robust and durable representative among domestic car engines. While the technology isn't top-tier, it excels in stability and affordability, with maintenance costs significantly lower than those of joint-venture brands.

I recall seeing the 4A91T designation in the workshop repair manual. This is a turbocharged engine primarily developed by Mitsubishi, now most commonly used by Soueast Motors. When servicing vehicles like the DX7, you can spot this model identifier by simply opening the hood. It's a practical choice among 1.5T engines, with a down-to-earth power tuning that delivers steady performance in city driving without feeling sluggish on highways. However, there are a few common issues to note: first, the crankcase ventilation valve tends to malfunction, often leading to excessive oil consumption; second, the turbocharger pipes may crack over time, causing power loss. During maintenance, it's recommended to inspect the timing chain every 30,000 kilometers, and using full synthetic oil can significantly extend the turbo's lifespan. For daily driving, this engine is quite reliable, with fuel consumption typically around 7-8 liters per 100 km, making it ideal for family commuting.

Last year, my Soueast DX3 came equipped with the 4A91T engine, and after driving over 20,000 kilometers, I've gained quite some experience. This Mitsubishi-derived 1.5T engine feels nimble at startup, and the push-back sensation kicks in after 1700 rpm. What I'm most satisfied with is the fuel consumption—around 7.5L in the city and just over 6L on the highway. However, the engine noise insulation is average, and the turbo sound is noticeable during rapid acceleration. During a previous maintenance session, the mechanic reminded me that the spark plugs on this engine need frequent replacement, preferably with iridium ones. Also, avoid using low-octane gasoline, as it can easily trigger the fault light. Overall, the reliability is good, perfectly adequate for daily commuting, and the power is significantly stronger than naturally aspirated cars in the same price range.

Having test-driven several models equipped with the 4A91T engine, this powertrain proves quite distinctive. As a Mitsubishi-designed turbocharged unit, it features centrally-mounted direct injection technology, delivering 156 horsepower with impressive low-end torque. During testing in the Soueast DX5, throttle response was more sensitive than expected, with brisk acceleration up to 60 mph. The downside is somewhat coarse engine noise at high RPMs, suggesting later installation of sound insulation foam. Fuel adaptability remains stable - 92 octane gasoline suffices completely, though turbo coolant must be replaced every 40,000 km. For SUVs in the 100,000 yuan price range, this powertrain balances economy and practicality well, with maintenance costs remaining budget-friendly.


