[Vwdiesel] 1.6TDI

[Roger Brown]

LBaird119 at aol.com wrote:
>   Well....
>   The first problem I see is that the TDI is DIRECT injected.  
> DI engines have the combustion chamber in the piston so there's 
> a big (relatively) dish in it, which usually leads to a taller pin to 
> top distance.  Put a DI head on a prechamber block and you 
> end up with no combustion chamber!
>   Dad's Passat is bigger, heavier and has similar power to my 
> Jetta or Rabbit (more power at highway speed usually.)  I'm 
> getting 42 with the Jetta, usually get mid 40's with the Rabbit, 
> and he got 55mpg the last tank and was generally getting 47mpg
> prior to a new air filter and a couple other things.  I usually got 
> 42 even with cruise control.
>   Our experience shows no loss, actually a gain from the bigger 
> engine and TDI.  The 1.9 NA and TD's seem to make a little lower 
> mileage than the 1.6's.  Of course I always felt the 1.5's did better 
> than the 1.6 but I don't attribute it to displacement.
>      Loren

I think part of the TDI's fuel economy comes from the taller gearing in the transmissions.  They turn over pretty slow at 
cruising speeds and the engine is tuned to hit peak torque around 1900 RPM.  Once I get my FN transaxle regeard to a 3.67 final 
drive, I hope to see a MPG increase in my Caddy.  I hope to drop the highway revs down closer to the peak torque point (2400 on 
the 1.9D).

-- 
    Roger