[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
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 . . .