My Westfalia's present setup is as follows:
Winter tires, 215/75-15 BS Blizzaks on Passat steel wheels, 45mm offset
Three-season tires, 235/75-15 BS Dueler A/Ts on SA 'Wolfsburg' alloy wheels,
30mm offset
The transmission has only one modification, the .77 fourth ratio
The engine is a slightly modified 1.9 litre intercooled turbodiesel

My driving experience with this setup:
Depends a lot on the air quality! The TD on 'good air' days, i.e. dense air,
pulls a LOT harder! (That variable will soon change, with the addition of an
air-to-water intercooler) Using the 215s OR the 235s, the van is able to
pull any hill better than it ever did with the combination of waterboxer,
stock gearing, and 27x8.5-14s. I can easily cruise up most interstate grades
at 70 to 75 mph, surprising the truckers that see a VW van at the start of a
grade and immediately pull left to pass! Only a long extended highway climb
gets it down, even then it only drops to 55 mph. The approximate gearing is
now 3100 rpm at 70 mph, although I have yet to measure that precisely. It
will cruise quite easily at 75-80 mph if I choose, even 4000 rpm comes up
easily in top gear with the 235s! The handling with the 235s is great, good
response, work extremely well off-road, decent ride. The 215 snows ride well
also, but give up a lot in the response department on dry roads; when in
their element, they are truly wonderful tires!

Karl Mullendore
Westy Ventures
1987 Syncro Westfalia 1.9TD

----- Original Message -----

> There are owners of 235/75-15 tires (with stock North American gearing)
> that actually say they like that size notwithstanding the effect it has on
> gearing and acceleration. Comments to this effect came came to me by email
> after I cast doubt on the suitability of this size for *any* vanagon
> owners, even syncro owners who go off road. It is, after all, somewhere in
> the region of 3" taller or more than the stock tire that came on the
vehicle.
>
> The issue is important in deciding what tires and gears go together well
> and which do not, a subject upon which I am still working. You will see an
> appeal for additional commentary from owners of 235/75-15 tires and
> 215/75-15 tires below.
>
> Since getting endorsements of the 235/75-15 tire sizes from some list
> members, I have also subsequently received additional comments from list
> members saying that while this tire is OK in gears 1, 2, and 3 it is not
> very suitable in 4th. Says the owner below, "I would not recommend this
> tire to anyone who lives near any hills." Added an earlier post about this
> tire, possibly inexact quote: "It was fine around town but on the highway
I
> had a hard time even getting it to 70."  This information is vitally
> important, because it affects the way owners should gear their vans in the
> future. Because the information about the undesirability of the 4th gear
> seems well stated and genuine, I am inclined to assign a fairly high
degree
> of credibility in these statements. See an owners report at the end of
this
> email that lends support to this conclusion.
>
> Accordingly, I am slowly deriving a principal that says that any gearing
> setup which would cause the vehicle to travel at an actual speed in 4th
> gear at 4,000 rpm of 78.8mph is a inadvisable setup unless some other
> variable is attached to it, such as a larger engine than 2.1 MV. But it
> seems to be slightly more acceptable that the vehicle may travel in 1st,
> 2nd, and 3rd gears 17.7, 32.5, 54.5 mph at 4000rpm, respectively, high
> though those numbers may be.
>
> For reference purposes, stock mph speeds for north american syncros with
> 4.86 final drive gears in gears 1 through 4 at 4000rpm are:
>
> 15.95, 29.28, 49.23, 70.95
>
> So what we are saying is a jump from 70.95mph 4000rpm 4th to 78.8mph is
> simply too great.
>
> If you have any information that contradicts the conclusion above, or have
> any impressions or observations to add, now is the time to do so as they
> will affect a body of work that will serve as a reference point going
> forward. In other words, it is important for you to post your feedback on
> this issue if you have any to give. This also applies to how well you like
> 215/75 BFGs if you are running that size. Ideally, I need comments on each
> gear rather than just "I liked the tire fine," but any comments are
welcome.