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Re: Bosch W7 DTC vs Bosch Platinum?

      I use the W5DTC in the 85 ur-q because the '5' heat range is correct for =
      the ur-q. The 5K/200 turbos use the '7' heat range, hence the W7DTCs in =
      the big Qs. I fergit if the 5 or the 7 is hotter/colder......my guess is =
      that the 5 is colder for less detonation at high boost.

   Bosch uses higher numbers for "colder" plugs (with "colder" generally meaning
   suitable for use in "hotter" engines...); 

   So I guess the factory specifies a hotter plug for the ur-q Vs the 5000/200TQ....? 
   That's the reverse of what I would have thought.

What?? Did I get it reversed? Drat . . .

Let's see . . . Champion is higher number == higher heat range == "hotter"
plug; that much I's *sure* about!

The guy at the parts counter *said* Bosch numbered opposite from Champion;
maybe he (and thus, *I*) was wrong? (He didn't have the DTC's in any event)

My UrQ [Audi, not Bentley] owner's manual calls out WR6DS (Champion N7GY)
plugs, which are moderately on the cool side (Champion "7" range same as
my Lotus Europa for street/commute usage). 

I haven't experimented with the Bosch plugs to verify the heat ranges,
I don't even remember [Oh, the shame of it!] which plugs I am running in
the UrQ right now...other than they are burning nicely (medium brown/tan).

It certainly doesn't make sense to me that Audi would spec "hotter" plugs
on an UrQ re 5000/200T's! If Audi recommends 7's for the "family" cars,
and 6's/5's for the UrQs, that sounds to me like the Bosch works the same
as the Champions, to wit, lower number == lower heat range == "colder"

With increased boost/power from the engine, you definitely want a colder

Hmmm . . .