Date:         Wed, 6 Mar 2013 15:33:10 -0800
Reply-To:     Stuart MacMillan <stuartmacm@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Stuart MacMillan <stuartmacm@GMAIL.COM>
Subject:      Re: Slider Extension-Really large tires and related expenses!
Comments: To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
In-Reply-To:  <BAY152-ds43FA2ECF1338A95B5858AA0E40@phx.gbl>
Content-Type: text/plain; charset="utf-8"

Ouch, what a buzz kill Dennis!  However it's true due to the laws of physics.  Increasing tire size increases the amount of leverage (torque) needed to turn the wheels and move the van, placing more stress on the drivetrain.  Going from a 14" wheel to a 16" wheel increases the torque requirement proportionately by about 15%.  A quote from a four wheeling site sums it up better than I can:

"Increasing the tire size sets up a chain reaction in the system.  It increases the leverage exerted by the tire against components, it reduces the rpm of the engine at a given speed by reducing the number of rotations per mile of the tire and increases ride height and ground clearance.  Possibly moves the engine out of the power band that it likes to operate in and even creates errors in your speedometer and odometer."

Stuart

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Dennis Haynes

The expenses may just be starting with those tires and other modifications. Now you will get to break parts inside that rebuilt transmission. The differential output shafts and low (granny) gear housing are the parts that now can break on command. You will next find that you need a brake upgrade. Engine upgrade and ring and pinion changes are common with this tire size. But they do look cool. 

Dennis 

-----Original Message-----
Thanks to all of you for your responses. I had no idea that this mod would be so expensive! In the end, I went ahead and ordered 6,  245/75/16s and crossed my fingers.