Today wasn't a fairy tale at all (maybe because I didn't wear a dark gray T-shirt (H)). I went to somebody who owns a 2007 4-cyl EFI cultus and read it all and took photographs for you people. The manual was dated July 2007.
The standard spark plug is indeed NGK BP6ES, as somebody told me. (That somebody has a 2010 cultus, don't know which revision of manual.) The Denso part number is W20EP-U. Again, EFI systems always require a resistor-fitted spark plug.
I thought maybe the manual is for 3-cyl G10 so looked on engine specification page and found out that engine name and no. of cylinders is correct.
The standard gap is 0.7-0.8 mm, which is surprising since majority EFI systems (not only Suzuki but other manufacturers also) suggest a standard gap of 1.0-1.1 mm.
The standard replacement interval is 10,000 km or 6 months. The image is very blurry due to my cameraphone but since I've read in actual so I know what I'm telling is true :). This is also easily verifiable since BP6ES is the standard spark plug for FX, Mehran, Bolan, Ravi and Cultus 3-cyl carby G10.
Interestingly lower on this page (not readable by you people due to all that blurriness) there are listed items such as carburetor cleaning etc., whereas we all know that for EFI systems the term throttle body is used.
The severe driving conditions plug replacement interval is also 10,000 km or 6 months, only severe driving condition F: Use of leaded fuel applies.
I highly suspect that the manual is not properly updated, because it's been years and years since tachometer is factory-fitted with cultus and all sketches of dashboard show the older one.
Also noted that on page 67, the engine shown (highlighted) is 4-cyl.
But the air-cleaner box shown on some other page (unfortunately my hand has hidden the page number) is older one. IIRC, the G10B has a rectangular box just like other EFI cars of so many different manufacturers.
Hence I conclude that the manual has been inconsistently and halfheartedly updated. Some of the things are up-to-date, such as picture of engine, but other things such as instrument panel and very obviously spark plug designation have not been updated.
On a side note, there was a supplement for CNG kit along with the manual (which does not give any other information about spark plugs, I might add).
