Straight from the factory training release.

The LPi engine has 12:1 compression ratio by use of domed pistons with intake and exhaust valve reliefs. The top ring is LPi specific. The piston pins are fully floating.

The valve seats are LPi specific to prevent seat wear. The head its self is the same casting as the petrol engine but will have a '5' etched into the front right for identification.

The LPi engine uses the same spark plugs as the turbo engine.

ECOLPI SERVICE REQUIREMENTS
At the „A‟ service there are extra checks to be performed on EcoLPi vehicles
 Check DTC‟s.
 Check fuel lock offs.
 Check supply line connections.
 Inspect filler valves.
 Check LPG tank connections.
 Check injector & FRA connections.


There are extra items on EcoLPi vehicles that are to be replaced at specified intervals;
 Every 30,000km replace the air cleaner element.
 Every 45,000 km check the AFL operation.
 Every 60,000 km replace the supply line fuel filter.
 Initially at 15,000 km and after every 90,000km check all mounting points for tightness.


DTC’s
The DTC‟s need to be checked at every service for vehicles fitted with EcoLPi engines. The PCM automatically performs system integrity self tests as described in lesson 2. These test for internal and external leaks and if the PCM detects a leak will register DTC‟s.

What plug change interval do Ford specify for EcoLPi engines with the factory plugs?

Ford say 150 000km, I doubt that will work out in the real world though. They didn't get it right the old gas cars either.

I would hazard a guess that one would be lucky to achieve 100,000km per set of plugs, as per aftermarket conversions and Bosch double platinum plugs etc.

I'd be inclined to pull and inspect the plugs at 40 000km and 80 000km.
At 40k just to put some anti seize on them. At 80k because that's when I think they are going to become a problem.

It wouldn't hurt to put some die electric grease inside the plug boots at 40k too.