I’ve driven many new Mercedes models and have come to the conclusion that this brand does steering better than anyone right now. From a Metris Van to a GLE…MB steering has a way of being light and very accurate. Very little steering effort and corrections are needed. Kind of weird not many journalists mention this as far as I know.
Does anyone know what makes their steering so good? Mechanical parts or calibration?
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.
As a owner of a Civic Type R that has 3 unique settings for the steering feel I agree, there is a ton of customization possible with a EPS rack. The “heavy” setting is by far my favorite, it eliminates unwanted inputs from bumps and grooves in the road.
As a mechanical engineer in steering for an OEM this is a very well written response. Gone are the days of swapping valve grinds and t-bars!
How do you feel about some of the earlier applications of EPS, especially in Honda and Acura products if you have any knowledge. I really enjoyed my Acura TSX’s steering as long as I have great tires on despite its slightly dead on-center feel. Really looking to find something similar in a similarly reliable, luxury vehicle before I buy an older hydraulic equipped model.
Mercedes made the jump to Michelin tires a while ago and the steering feel benefited. Especially on Cup 2 applications.