Wikipedia notes concerns about Stop-Start systems:
"Concerns
The US National Highway Traffic Safety Administration (NHTSA) raised questions about non-hybrid Honda vehicles equipped with the company's 'Idle Stop' transmissions in February 2001 due to concerns over the "sudden lurching forward of a vehicle in an automatic restart" – rather than the "gradual creeping forward found in current transmission designs."
Hybrid/electric assist vehicles experience almost no delay in power from a stop, due to the instant availability of power from the traction battery to the electric motor(s). Gasoline/microhybrids on the other hand generally experience slight delays (albeit fractions of a second).
Many people think that long-term use may induce additional wear due to lack of oil lubrication. For the crankshaft bearing half shells and the big end bearings this can translate into frequent high-speed rotary movement before a hydrodynamic film is established. During this phase of boundary lubrication, metal-to-metal contact can occur between the crankshaft surface and the bearing's sliding surface. This was not an issue while the number of engine restarts totaled at what was generally understood to be a normal magnitude. However, in a vehicle with start-stop system this effect can necessitate new technological solutions to avoid premature bearing wear, depending on the driving cycle. Consequently, future engines for start-stop applications need to be designed for 250,000 to 300,000 starts. Traditional bearing shells with aluminum or copper lining show severe wear after only 100,000 cycles. In a start stop system the short stop times keep the engine and oil warm, retaining lubrication. Some implementations do not use a starter motor[citation needed], eliminating concerns of starter motor wear. Mazda i-stop used in their Mazda3/Axela line (in Europe and JDM) uses combustion to assist the starter motor by sensing the position of the piston in the cylinder. They claim quieter and quicker engine restart within 0.35 seconds.
Start-stop systems are heavily reliant on the battery. Testing indicates that AGM batteries diminish in their ability to support start-stop functionality over time. While alternatives exist (NiZn, Lithium-Ion, supercapacitors, PbC), virtually all automakers continue to use conventional AGM lead acid batteries.
Some car makers such as Suzuki have one lithium-ion battery inside the car."
2020 3.6 XT5s will have a stop-start defeat switch which must be actuated every ignition cycle.
"Concerns
The US National Highway Traffic Safety Administration (NHTSA) raised questions about non-hybrid Honda vehicles equipped with the company's 'Idle Stop' transmissions in February 2001 due to concerns over the "sudden lurching forward of a vehicle in an automatic restart" – rather than the "gradual creeping forward found in current transmission designs."
Hybrid/electric assist vehicles experience almost no delay in power from a stop, due to the instant availability of power from the traction battery to the electric motor(s). Gasoline/microhybrids on the other hand generally experience slight delays (albeit fractions of a second).
Many people think that long-term use may induce additional wear due to lack of oil lubrication. For the crankshaft bearing half shells and the big end bearings this can translate into frequent high-speed rotary movement before a hydrodynamic film is established. During this phase of boundary lubrication, metal-to-metal contact can occur between the crankshaft surface and the bearing's sliding surface. This was not an issue while the number of engine restarts totaled at what was generally understood to be a normal magnitude. However, in a vehicle with start-stop system this effect can necessitate new technological solutions to avoid premature bearing wear, depending on the driving cycle. Consequently, future engines for start-stop applications need to be designed for 250,000 to 300,000 starts. Traditional bearing shells with aluminum or copper lining show severe wear after only 100,000 cycles. In a start stop system the short stop times keep the engine and oil warm, retaining lubrication. Some implementations do not use a starter motor[citation needed], eliminating concerns of starter motor wear. Mazda i-stop used in their Mazda3/Axela line (in Europe and JDM) uses combustion to assist the starter motor by sensing the position of the piston in the cylinder. They claim quieter and quicker engine restart within 0.35 seconds.
Start-stop systems are heavily reliant on the battery. Testing indicates that AGM batteries diminish in their ability to support start-stop functionality over time. While alternatives exist (NiZn, Lithium-Ion, supercapacitors, PbC), virtually all automakers continue to use conventional AGM lead acid batteries.
Some car makers such as Suzuki have one lithium-ion battery inside the car."
2020 3.6 XT5s will have a stop-start defeat switch which must be actuated every ignition cycle.
