Tech - Dec 2019

Is the 48Volt Mild-Hybrid System the future?

Notably, in many of the new and imminent 2020 chassis and models are the inherent use of a “48Volt Mild-Hybrid system” that allows for energy recuperation and regeneration in a way that merges standard engines and electric/hybrid systems.

Systems make use of a belt-driven starter generator that serves as the traditional starter for the engine but also serves as a generator. Energy is stored in 48V lithium-ion batteries and kinetic energy is recycled in converted into electrical current that drives the motor and improves the dynamics of Stop/Start tech, through better and higher speed engine deactivations.
Systems have small differences in how they operate but the basic principles remain. The MEHV (Mild Electric Hybrid Vehicle) is becoming a phrase that we should all become rather familiar with given its application. I’ve driven a few cars with this system at this point, and frankly, the benefits of what is claimed in fuel consumption are rather small at present, but the additional boost is something that is best felt and offers real value, despite weight considerations.

The best application of this tech that I have sampled thus far is the Mercedez E53 AMG, being the first of the AMG model line up,
Affalterbach’s 3litre inline six-cylinder petrol “twin forced induction” engine boosts 320Kw and 520 Nm with the system adding 16kW and 250Nm under “EQ boost”.
Practically this means you start the car and it’s an almost instantly the engine comes alive. It’s a very swift process which is important given this works with a stop/start system that allows for when lifting off the throttle the engine switches of and the car glides making use of the system even it speed.

Given the systems ability to shut off the engine the idea is fuel consumption, lower emissions and the ability to use smaller engines to provide power akin to much bigger motors. The issue is the system does work, but in the real world the re-gen is there and you find the cruising on the freeway with the engine off a bit of an adjustment, but a stab at the throttle and it awakens very quickly. This is all well and great but the issue of additional weight given the need for extra equipment and more importantly the scary notion of how many performance offerings now have or will have this system make it a somewhat of a controversial yet interesting move. VW’s Golf 8 will employ the same tech in a large portion of the range and its growing in popularity across the board so the tech is only going to grow and advance.

The argument simply the power advantage vs economy advantage, some of these systems and the EQ boost abilities make the system rather important in that they can transform the performance as 250Nm is no easy feat. Understand this its a cheat code to power and I feel most cars will adopt this in some way and with some refinement and the advancement it will likely see through the major manufacture support it has will become a very common thing. The E53 AMG, for example, is a torque monster and overtaking in this car makes it feel far more rapid than the numbers suggest. Obviously, there will be no replacement for displacement and the E63 would make this car a tiny spec in the rearview, but it makes this a far better car and makes a lot of sense once you’ve sampled the tech.

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