Which is more fuel-efficient: H4F, H4L, or L4L?
3 Answers
H4F is the high-speed gear, suitable for normal daily use and relatively fuel-efficient. H4L is the low-speed gear, used for climbing slopes and consumes more fuel. H4F, H4L, and L4L are three modes of the four-wheel drive system. Below are the relevant introductions: Introduction to H4F: H4F is the full-time four-wheel drive mode with an open center differential, suitable for highway driving without speed restrictions and no turning limitations. It offers better handling on slightly slippery surfaces such as rain or snow. Introduction to H4L: H4L is the full-time four-wheel drive mode with the center differential locked, eliminating differential between the front and rear axles. It is not suitable for high-speed driving on paved roads but is ideal for very slippery surfaces. Steering should be gentle, and the steering wheel will feel heavy. Using this mode on insufficiently slippery surfaces can cause wear and tear on drivetrain components, damaging the vehicle, so speed should also be kept low. Introduction to L4L: L4L is the low-speed four-wheel drive mode with the center differential locked and low-speed torque amplification, providing greater torque output than L2. It is used for extrication in extreme off-road conditions but must be operated at low speeds only.
I often drive my SUV in the city and on highways, and I've found that H4F mode is the most fuel-efficient because it only engages four-wheel drive when necessary, otherwise operating more like rear-wheel drive, significantly reducing drivetrain loss. In contrast, H4L is a high-speed locked four-wheel drive mode, requiring the engine to constantly power all wheels, increasing friction and raising fuel consumption by 10% to 15%. L4L is specifically for off-road steep climbs—once locked in low gear, the engine has to rev high to climb, causing fuel consumption to skyrocket further. For everyday driving, sticking with H4F is the economical choice, especially for long commutes, where you can noticeably save on fuel costs. If tire pressure is optimal and the vehicle is well-maintained, H4F operates even more efficiently. Remember to switch to H4L only during rain, snow, or rough roads to improve traction, but be prepared for faster fuel consumption.
With decades of driving experience, H4F is undoubtedly the most fuel-efficient setting for flat-road driving. My habit is to use H4F for highway cruising, as it reduces unnecessary drivetrain losses, keeping fuel consumption stable at normal levels. H4L mode, however, consumes more fuel due to higher engine load, especially on uphill or slippery roads where it guzzles more. L4L is low-range locked 4WD, ideal for off-roading to escape muddy situations, but it doubles the RPM and drains the fuel gauge quickly. I recommend practicing mode-switching techniques: use H4F for dry highways to save fuel, and switch to the other two modes only when road conditions worsen. Keeping the engine well-maintained with fresh oil can further optimize H4F’s efficiency. In the long run, mastering these modes can significantly cut fuel expenses.
