Date:         Thu, 28 Mar 2002 21:21:08 EST
Reply-To:     FrankGRUN@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Frank Grunthaner <FrankGRUN@AOL.COM>
Subject:      Re: Comment on 2.1 WBx vs. 2.2 Sub vs. Tiico (Fuel Efficiency)
Comments: To: afox@cnr.colostate.edu
Content-Type: text/plain; charset="US-ASCII"

In a message dated 3/28/02 10:18:20 AM, afox@cnr.colostate.edu writes:

<< Wait you forgot to mention that its extremely inefficient (poor gas
mileage), and is prone to Vanagon syndrome. >>

Actually, I said that its ability to generate a Brake Mean Effective Pressure
was competitive with the others (same combustion chamber efficiency and
similar pumping losses. Fuel efficiency is yet another matter. Of course,
there are all kinds of anecdotal comments about fuel economy (most of which
are bogus - or well meaning cracker barrel stories). The real issue is the
Brake Specific Fuel Consumption curve which shows how much fuel is required
for the engine to do a unit amount of work. These curves show full and part
throttle efficiency as well as optimal operating points. These curves for the
1.9 and 2.1L WBx engines are in the German design articles on Alistair's
website, as are the curves for the NA and Turbo Diesel as well as the 1.8L
digifant and CIS engines. Of course, the Japanese don't deign to share this
data with us, but perhaps it exists with the aircraft engine modifiers.

I went on about fuel efficiency in the archives now and more details are
there. I have translated an excellent VAG article on engine design and
operation issues for optimal fuel economy and hopefully Alistair will be able
to post it soon. That said, the 2.1 in factory tune has nothing to be ashamed
about in BSFC!

So, nope, ain't that bad if running right!

Frank Grunthaner