I’m an Electric Power Steering (EPS) tuner working for an OEM in the automotive industry. AMA.
In the days of EPS, it’s less clear how to explain how a particular vehicle or manufacturer achieves a certain steering feel. I think most drivers, including enthusiasts, vastly underestimate how much tunability there is in EPS and how widely the tuner can vary the steering feel keeping all things but software constant. Steering feel is almost completely subjective with only a few factors being universally agreed as objective areas that make steering feel better or worse. So, MB steering character might be excellent to some drivers while others don’t like it at all.
From my own evaluation of some of the MB vehicles mentioned in this thread, here’s my analysis:
The tire, being the part that touches the road and does the steering, will always have the largest effect on steering response and feel. MB tends to equip good tires that respond with little on-center delay and a linear response shape.
Having the assist motor mounted to the rack (instead of the column) helps, but it isn’t that simple. There isn’t anything inherently bad with column-mounted EPS, so long as the compliance is managed. Rack-mounted systems tend to be stiffer, which is better for response and gives the tuner more flexibility in parameters that the system can support, but the small differences in system compliance are usually only detectable by experts.
Geometry was mentioned by someone and it makes the list, but it isn’t the most significant factor. More trail creates more self-aligning torque in the wheel, which drivers will refer to as “more feel”, but it’s really just effort. Certain aspects of the geometry can promote or attenuate road feedback, but small potatoes. Clever steering tuning can trick drivers to think there is more or less trail, more or less response.
In my opinion, the biggest thing creating the MB steering character is the tuning. MB uses lots of assist with lots of damping. This creates a feel with a good amount of control and the combination of the “lightness” of the assist and “heaviness” of the damping gives a highly-filtered feeling of isolation that feels premium to some. The effort shape isn’t very steep and there’s no goofiness around center, so you get a linear, comfortable feel, even if it isn’t 100% matching what the tire is doing down below.
I’m an Electric Power Steering (EPS) tuner working for an OEM in the automotive industry. AMA.
In the days of EPS, it’s less clear how to explain how a particular vehicle or manufacturer achieves a certain steering feel. I think most drivers, including enthusiasts, vastly underestimate how much tunability there is in EPS and how widely the tuner can vary the steering feel keeping all things but software constant. Steering feel is almost completely subjective with only a few factors being universally agreed as objective areas that make steering feel better or worse. So, MB steering character might be excellent to some drivers while others don’t like it at all.
From my own evaluation of some of the MB vehicles mentioned in this thread, here’s my analysis:
The tire, being the part that touches the road and does the steering, will always have the largest effect on steering response and feel. MB tends to equip good tires that respond with little on-center delay and a linear response shape.
Having the assist motor mounted to the rack (instead of the column) helps, but it isn’t that simple. There isn’t anything inherently bad with column-mounted EPS, so long as the compliance is managed. Rack-mounted systems tend to be stiffer, which is better for response and gives the tuner more flexibility in parameters that the system can support, but the small differences in system compliance are usually only detectable by experts.
Geometry was mentioned by someone and it makes the list, but it isn’t the most significant factor. More trail creates more self-aligning torque in the wheel, which drivers will refer to as “more feel”, but it’s really just effort. Certain aspects of the geometry can promote or attenuate road feedback, but small potatoes. Clever steering tuning can trick drivers to think there is more or less trail, more or less response.
In my opinion, the biggest thing creating the MB steering character is the tuning. MB uses lots of assist with lots of damping. This creates a feel with a good amount of control and the combination of the “lightness” of the assist and “heaviness” of the damping gives a highly-filtered feeling of isolation that feels premium to some. The effort shape isn’t very steep and there’s no goofiness around center, so you get a linear, comfortable feel, even if it isn’t 100% matching what the tire is doing down below.