IMPORTANT NOTE: during Otto intake cycle:
assuming that)  p2 as dynamic intake cycle mean pressure exerted onto piston's crown (combustion chamber pressure)
and assuming that  
p1 as the VVICC's (variable volume of cylinder-crankcase) air pressure of a cylinder performing its intake cycle
we then get: :   
(p1 - p2)   =   Otto intake-cycle Δp CONDITIONS  

same* as GDI fuel system
Δp  >0  condition (larger than zero)                  Δp  =0  condition (equal to zero)                    Δp  <0  condition (less than zero)

NO-PUMPING-LOSS condition when ∆p  = 0  (is equal to zero)
U.A.I.C.  UNCONTROLED AIR INTAKE CYCLE: previously only provided by GDI direct fuel injection fuel system
conveniently applicable to non-compressible liquid fuel (gasoline, ethanol, etc.)

Note : NO-PUMPING-LOSS condition possibility can also now be achieved with Light Turbo Compound engine variant system
LTCev) Canadian Patent  CA 2,732,477 & US patent 8,683,987

and is not only applicable to non-compressible liquid fuel (gasoline, ethanol, etc.)        
but it is also uniquely applicable and well suited for compressible gaseous state fuels   (natural gas)   
Note: State of the art direct fuel injection system still faces some unresolved challenges to suitably inject a lighter gas (natural gas)
directly into the cylinder filled by a denser & heavier air medium
NGV Global News   

Emerging Light turbo Compound Delta-P
turbocharger-derived technology
New Potential Insight
into Otto's intake-cycle advantagous VVICC's under-pressure-conditions optimization
for higher specific fuel efficiency's enhancement related to taking advantage of available ambient
barometric pressure potential of normally aspirated & charged cylinder's pressure during intake
cycle of Otto cycle I.C.E.

The 3 new advantageous unique patented possibilities provided by  I.C.O.A.P. induction strategy are as follow:

to provide to controlled-air ( throttled) Otto CAIC engines substantial reductions of pumping task friction by neutralising pumping-loss friction at moderate engine
useful part-load and as engine power is progressively increased beyond mid-engine load, to provide means of optimise pumping-gain-assistance) in order to provide
the highest fuel
efficiency possible without increasing NOx emissions.
This allows a CAIC (throttled) Otto Cycle engine  to partially emulate  at higher-part-load & mid-load'  the "NO-PUMPING-LOSS-FRICTION " fuel saving
equivalent advantage normally only provided by UAIC engines using Direct Fuel Injection system). It can also provide the CAIC engine a very beneficial
"PUMPING-GAIN" at sustained higher engine loads
    it provides said  CAIC (throttled) Otto Cycle engine with indirect-pneumatic-coupling beneficial "PUMPING-GAIN ASSISTANCE:
    a unique turbo-compound engine's fuel saving advantage effective progressively beyond idle mainly
    from ~ mid-engine load right to full-engine load
    PUMPING-GAIN takes advantage of the available ambient atmospheric pressure assistance force means exerting indirect -pneumatic- coupling
    force as new means of pneumatic pumping-assistance taking place during Otto intake cycle in the VVICC.
    I.C.O.A.P   Optimized Intake Cycle Air Pressures  induction strategy UNIQUELY allows a UAIC engine GDI ( direct fuel injected ) both the S.I. D.I. (
    gasoline) and the C.I.D.I. (diesel)  operation to nearly double their natural intake cycle air  pumping task's ease, this further improve
    specific fuel efficiency due to assistance from indirect pneumatic coupling available from moderate engine load to full load.

Otto cycle internal combustion engines, are generally classified as  being of
S.I. or C.I  types: for  
S.I. spark ignition  & C.I. compression ignition
Otto cycle internal combustion engines used two major intake cycle induction charging modes that are usually referred as:
Normally Aspirated induction   &  Charged induction (forced-air) by means of supercharger,turbocharger or wave compressor  
until recently, Prior art Otto cycle internal combustion engines mostly used only two intake cycle air-control induction strategies:
the C.A.I.C. induction strategy  &  the U.A.I.C. inducion strategy

    C.A.I.C.  induction strategy refers to: controlled-air intake cycle induction strategy
    (all throttled fuel control systems),including VEMB valve control systems such as:
Fiat MultiAir    BMW Valvetronic    Honda VTEC       Nissan VVEL,     Toyota Valvematic,      :

    U.A.I.C.  induction  strategy refers to: uncontrolled-air intake cycle induction strategy
    (S.I.D.I.   Spark Ignited direct fuel injection system) in stratified  or homogeneous mode   (gasoline GDI)
    (C.I.D.I.  Compression Ignited direct fuel injection system)  common-rail diesel fuel (Diesel CDI)

     Now, Otto cycle I.C.E.'s induction strategies can include :
I.C.O.A.P.  that refers to: Intake Cycle Optimised Air Pressures strategy providing
new higher Otto cycle fuel efficiency possibilities to both Otto cycle
S.I.- C.I.  
CAIC & UAIC induction engines:  
during Otto intake cycle at engine part-load
(p1 - p2) = Δp  > 0
detrimental  PUMPING-LOSS-FRICTION conditions prevail   when ∆p is larger than zero

resulting from Prior Art  C.A.I.C. or CONTROLED AIR INTAKE CYCLE   
(using any mean to control intake cycle air flow)
i.e. ( all throttled fuel system including VEMB )      : BMW Valvetronic    Nissan VVEL,     Toyota Valvematic,    Fiat MultiAir
Imprtant LTCev potential can reastically being foreseen: a significant essential
higher specific fuel efficiency and GHG reduction at engine part-loads proven
potential combined with reduced NOx, CH4* and Formadehyde Raw Emissions may
be envisioned for accurate timely  adjust  for variable energy load eletrical power grid
requirements due to peak and valley power demands for portable genset gas
engines as well as more fuel efficient large giant stationary Reciprocating Piston
electrical Genset gas engines supporting  Areoderived natural gas turbines (Genral
Electric) natural gas turbines genset in majors electricity power centrals and also
important and essential for large transport ships's large marine bi-fuel Gas Engines
*raw CH4* slip emissions control (In development)
Reciprocating Piston
      Gas engine
Wartsila’s 18V50DF dual fuel engine
"indirect pneumatic coupling process" may be emerging as green era paradigm for cost effective
sustainable mobility Otto cycle I.C.E Genset component for affordable light electric hybrid vehicles
as well as for CNG conventional light,  medium, and large displacement capacity essential electrical grid
services genset emergency I.C.E. .
Note to reader:
To protect the LTCev pending technological
and related projected patent
prosecution, some aspects are
intentionally not  to be  divulged here .
at this time
Reciprocating piston Rolls Royce Geset natural gas engine
Wartsila F 46
reciprocating piston
   gas engine
Note: LTCev (as a supplemental adiabatic system) capable to provide Intake cycle pumping-gain assistance
can significantly contribute to facilitate meeting:
U.S. EPA’s CAFE rule for MY2017-2025  due to its advantageous cost effective  compatibility with
most state of the art implied and solicited technologies.

useful references
A mix of current- and next-generation technologies will enable automakers to go from the present combined light-duty fleet average of 27.3
mpg to 54.5 mpg in 2025, according to officials with Ricardo Inc., an engineering services and consulting company that had input on the U.
S. EPA’s CAFE rulemaking for MY2017-2025.

Ricardo’s technology roadmap for 2025 shows that vehicles powered by internal-combustion engines with three, four, or more cylinders will
use various combinations of advanced boost systems, direct injection, and advanced valvetrains to facilitate performance and boost fuel
economy, according to John Kasab, Ricardo Chief Engineer of Innovations.

“An advanced boost application could be two-stage, series-sequential turbocharging or a turbocharger-supercharger combination—depending on
the transient performance requirements. For the valvetrain, Ricardo assumes cam profile switching will be typical by 2025,” Kasab told AEI.

Mark Kuhn, Ricardo Manager of Strategic Consulting, said that automakers and suppliers have not been sitting idle prior to the 2025
mandate, with several of them already in production with advanced valvetrain designs as well as turbocharging and direct-injection
technologies as a companion to downsized engines.

While MY2016 marks the next light-duty vehicle fleet federal mandate milestone (35.5 mpg), the MY2025 timeline looms as a heady task for

Said Kasab: “The main challenge for meeting the MY2025 targets is developing a cost-effective, holistic solution for the complete vehicle
or platform that can reduce losses in the engine, transmission, driveline, and vehicle. The cost considerations are why Ricardo sees the
most interest in improving engine efficiency and in lowering vehicle mass.”

Rolls_Royce Bergen reciprocating piston