GM & others Reduced I.C.E. Friction
 

Link
Very slick: Automakers strive to reduce engine friction - NWautos

General Motors has quantified the overall friction reduction for three of its four-cylinder engines. The 2007 2.4-liter four-cylinder generated 46 percent less friction in low-speed driving than GM's 2-liter four-cylinder of the early 1980s, despite having more valves, a more complex camshaft drive and a pair of counterbalancer shafts. Friction reduction alone resulted in about 7 percent better fuel economy over that 24-year period.

In the new 2.5-liter four-cylinder that will power the 2013 Chevrolet Malibu, friction has been cut another 16 percent, resulting in a 2 percent engine efficiency gain compared with the 2007 2.4-liter.

Each engine developed more power per liter than its predecessor, doing more

Interesting - thanks for posting that.

Friction reduction approaches mentioned in the article:

• cylinder-coating materials
  
  Quote:

  In the Nanoslide coating process, the cylinder walls are sprayed with an ultrathin layer of a molten iron-carbon alloy. A special finishing process puts a smooth surface on this extremely hard coating, at the same time opening tiny pockets in the metal that retain oil for lubrication.

• advanced honing techniques (abrasive & laser based)
• smaller bearings
• straighter chain runs (camshaft chain)

Internal coatings, optimization of the design of certain moving parts such as valve rockers, camshafts, among others, and also lighter alloys were a great advance.

One problem... these new anti-friction coatings and the lightweight engine blocks mean that re-boring and re-building these engines after they blow is sometimes a problem.

On the brighter side, engines nowadays typically last longer than most people keep cars.

That's a good point to consider while looking for cylinder sleeves...

...it's also a contention point when something goes wrong with the engine and they want to just "rebore' rather than replace the block under the warrantee!