Sprinter-Forum    
 

Go Back   Sprinter-Forum > Sprinter-Based RV's & Conversions > Sprinter-Based RV Brands > Roadtrek


 
Thread Tools Display Modes
Old 07-22-2012, 07:12 PM   #21
glas1700
 
glas1700's Avatar
 
Join Date: Oct 2006
Location: Woodside, CA
Posts: 812
Thanks: 66
Thanked 332 Times in 252 Posts
Default Re: incorrect pillar label (tire size and pressure)

To further muddy? the waters, Tire Rack lists a "rim width range" of 6.5" to 8" for a 245/75-16 tire, with a measured rim width of 7". So the wheels are at the minimum range of widths for this size tire, but would still be safe.
__________________
Byron
07 Itasca Navion
06 Sprinter 3500 Cutaway
97 Geo Tracker 4WD toad
glas1700 is offline   Reply With Quote
Old 07-22-2012, 07:13 PM   #22
sailquik
 
sailquik's Avatar
 
Join Date: Mar 2008
Location: Cape Hatteras, North Carolina
Posts: 8,769
Thanks: 3,026
Thanked 5,494 Times in 3,333 Posts
Default Re: incorrect pillar label (tire size and pressure)

NAFTA Sprinter Specs (per the "B" pillar sticker; the owners manual; and what mostly shows up on the
new Sprinters) are different between the 2 weight classes.
NAFTA NCV3 2500 series Sprinters with single rear wheels are specified with 245/75R16 tires that are 30.5" in diameter (683 rev/mile).
NAFTA NCV3 3500 series Sprinters with dual rear wheels (DRW) are specified with 215/85R16 tires that are also 30.4" in diameter (685 revs/mile.
Comparison was made on Continental Vanco Four Seasons which are the most common OEM tire.
So, the difference is the load carrying capacity of the wheels due to differences in wheel width, not necessarily in tire size.
2500 NCV3's use one kind of wheel (6.5J x 16 I believe) that can only be installed with the
offset inboard from the ends of the axles.
3500 NCV3's use a more universal wheel that can be mounted universally (offset inboard on the inner rears and fronts....offset outboard on the outer wheels (DRW).
NCV3 3500 Cab/Chassis for box truck/service body and RV conversions use a wider 16" wheel with a bit more offset.
Hope this clears up a little confusion.
Roger
__________________
2014 Sprinter 516 series (3500 DRW) 170"/4325 mm wb Hi Top Short Back
OM-651 I4 2.143 liter two stage turbo charged with 36.9 PSIA MAP Limit Valve
7 Speed 7G-Tronic, manually shiftable, automatic transmission.
Suspension Seats, Active Safety Package +, Parktronic, OEM Hitch/wiring
OEM back up camera, Bi Xenon light package, fog lamps, headlight washers.
Had 2006 T1N 3500/158|2010 NCV3 519/3500/144|2011 & 2012 NCV3 519/3500 170

Last edited by sailquik; 07-22-2012 at 07:23 PM.
sailquik is offline   Reply With Quote
Old 07-22-2012, 09:36 PM   #23
autostaretx
Erratic Member
 
autostaretx's Avatar
 
Join Date: Sep 2006
Location: Seattle
Posts: 17,567
Thanks: 3,079
Thanked 7,945 Times in 5,793 Posts
Default Re: incorrect pillar label (tire size and pressure)

Quote:
30.5" in diameter (683 rev/mile).
Just a note regarding diameter and revs per mile...
If you carry out the calculation (5280 ft/mi * 12 in/ft) / (683 rev/mi * Pi) = 29.53 inches effective diameter (or 14.76 radius, axle-to-road)

--dick
__________________
2005 T1N 118" Freightliner 2500 Passenger Wagon (2.7L, 15" tires, standard (short) roof)
Get YOUR Sprinter's full configuration datacard by entering your VIN to https://www.datamb.com/
http://diysprinter.co.uk/reference <-- lots of service documentation, Thanks to Jens Moller and Arnie_Oli
((as always: this post may go through a couple of post-posting edits... so maybe give it ten minutes before commenting))
autostaretx is offline   Reply With Quote
Old 07-22-2012, 09:59 PM   #24
sailquik
 
sailquik's Avatar
 
Join Date: Mar 2008
Location: Cape Hatteras, North Carolina
Posts: 8,769
Thanks: 3,026
Thanked 5,494 Times in 3,333 Posts
Default Re: incorrect pillar label (tire size and pressure)

Dick,
Noted!
The 30.4" and 30.5" diameters came straight off Tire Rack.com/specs for Continental
Vanco 4 seasons (identical tires....different size and aspect ratios).
I suspect the revs/mile may loaded @ normal inflation pressure, so the radius could
be less as the tires flatten a bit on the weighted side.
Might explain the discrepancy.
Roger
__________________
2014 Sprinter 516 series (3500 DRW) 170"/4325 mm wb Hi Top Short Back
OM-651 I4 2.143 liter two stage turbo charged with 36.9 PSIA MAP Limit Valve
7 Speed 7G-Tronic, manually shiftable, automatic transmission.
Suspension Seats, Active Safety Package +, Parktronic, OEM Hitch/wiring
OEM back up camera, Bi Xenon light package, fog lamps, headlight washers.
Had 2006 T1N 3500/158|2010 NCV3 519/3500/144|2011 & 2012 NCV3 519/3500 170
sailquik is offline   Reply With Quote
Old 07-23-2012, 01:19 AM   #25
talkinghorse43
 
Join Date: Dec 2006
Location: near Pittsburgh, PA
Posts: 3,184
Thanks: 425
Thanked 957 Times in 694 Posts
Default Re: incorrect pillar label (tire size and pressure)

Quote:
Originally Posted by sailquik View Post
Dick,
Noted!
The 30.4" and 30.5" diameters came straight off Tire Rack.com/specs for Continental
Vanco 4 seasons (identical tires....different size and aspect ratios).
I suspect the revs/mile may loaded @ normal inflation pressure, so the radius could
be less as the tires flatten a bit on the weighted side.
Might explain the discrepancy.
Roger
Load/inflation pressure shouldn't affect circumference. Circumference determines revs/mile.
__________________
'02 316 2500 SHC FTL 140 passenger, NAG1, 3.73 diff, 16" wheels, OM612 w/EGR (>415k mi.), '04 Golf PD-TDI (>160k mi.), both bought new
talkinghorse43 is offline   Reply With Quote
Old 07-23-2012, 03:09 AM   #26
autostaretx
Erratic Member
 
autostaretx's Avatar
 
Join Date: Sep 2006
Location: Seattle
Posts: 17,567
Thanks: 3,079
Thanked 7,945 Times in 5,793 Posts
Default Re: incorrect pillar label (tire size and pressure)

Quote:
Load/inflation pressure shouldn't affect circumference. Circumference determines revs/mile.
Radius determines *effective* circumference.
Load requires (load divided by pressure) square inches to contact the road to carry that load. (more or less, with arm-waves for tire pattern and rubber/belt strengths)
The tire has to squish down (shorter radius, more turns per mile) to bring the load-determined number of square inches in contact with the road.

During all of that, the *circumference* (if you measure it) doesn't change, but the revs/mile do...

At some super speed the tire would be brought out to near-circular, but then it would be the centrifugal force carrying the Sprinter's weight, not the tire's internal pressure.
If you don't believe load/pressure change the revs per mile, think of the "flat tire" situation.. .the road-side tire radius shrinks (to the metal wheel), but the above-wheel radius doesn't change.

--dick
__________________
2005 T1N 118" Freightliner 2500 Passenger Wagon (2.7L, 15" tires, standard (short) roof)
Get YOUR Sprinter's full configuration datacard by entering your VIN to https://www.datamb.com/
http://diysprinter.co.uk/reference <-- lots of service documentation, Thanks to Jens Moller and Arnie_Oli
((as always: this post may go through a couple of post-posting edits... so maybe give it ten minutes before commenting))

Last edited by autostaretx; 07-23-2012 at 03:16 AM.
autostaretx is offline   Reply With Quote
Old 07-23-2012, 03:29 AM   #27
talkinghorse43
 
Join Date: Dec 2006
Location: near Pittsburgh, PA
Posts: 3,184
Thanks: 425
Thanked 957 Times in 694 Posts
Default Re: incorrect pillar label (tire size and pressure)

Quote:
Originally Posted by autostaretx View Post
Radius determines *effective* circumference.
Load causes (load divided by pressure) square inches to contact the road to carry that load. (more or less, with arm-waves for tire pattern and rubber/belt strengths)
The tire has to squish down (shorter radius, more turns per mile) to bring the load-determined number of square inches in contact with the road.

During all of that, the *circumference* (if you measure it) doesn't change, but the revs/mile do...
So, you agree the 1-rotation tread length (circumference) is constant. If the 1-rotation tread length is constant, then how can the rotational speed change when the tire is deformed? I don't think the tread looses contact with the road or skids a little every rotation to make up the difference.
__________________
'02 316 2500 SHC FTL 140 passenger, NAG1, 3.73 diff, 16" wheels, OM612 w/EGR (>415k mi.), '04 Golf PD-TDI (>160k mi.), both bought new
talkinghorse43 is offline   Reply With Quote
Old 07-23-2012, 04:01 AM   #28
CJPJ
2008 3500 170"ext. 3.0 V6
 
CJPJ's Avatar
 
Join Date: May 2010
Location: Contra Costa California, Douglas County, Oregon
Posts: 3,907
Thanks: 3,861
Thanked 2,009 Times in 1,315 Posts
Default Re: incorrect pillar label (tire size and pressure)

Comparative comparability comparison! [quote=cjpj;171083]
tire size____________ 215/85-16__________ 235/85-16
section width _______ 8.46" ________________ 9.25"
rim width range______ 5.5"-7" ________________ 6" -7"
overall diameter______ 30.38"________________ 31.72"
circumfrence________ 95.44"_________________ 99.65"
actual speed________ 60mph_________________ 57.4mph
spedometer diffrence_ 0%____________________ 4.407% too slow
diameter diffrence____ 0%____________________ 4.23%
revs per mile ________ 684.6__________________ 655.7
Quote:
Originally Posted by cjpj View Post
I see that the sprinter 3500 rim width of 5.5" is 1/2" under the recommended range of the 235/85-16 tire.

Being that the tires sidewalls are .67" taller and more askew to the rim, using a 235/85-16 tires on 5.5" rims will slightly slow the steering, and a reduction in stability will show up in cross winds as more sway, How much less stable, with slower response? Comparatively little, but noticeable!

I'm still considering the taller tire. I like the appearance in the wheel well of a larger tire. I like a small increase in the final drive ratio. I donít like clearance between the drw being small. Larger circumference tires last longer,shortens brake life, a small increase stress increase to power train and mother inlaw will have to step .67" higher to get into the sprinter. Good and bad to everything... I think Iím over thinking this!....
.

Last edited by CJPJ; 07-23-2012 at 05:05 PM.
CJPJ is online now   Reply With Quote
Old 07-23-2012, 04:12 AM   #29
sailquik
 
sailquik's Avatar
 
Join Date: Mar 2008
Location: Cape Hatteras, North Carolina
Posts: 8,769
Thanks: 3,026
Thanked 5,494 Times in 3,333 Posts
Default Re: incorrect pillar label (tire size and pressure)

CJPJ,
Did you calculate all your values here, or is this from a particular brand and model
from one of the tire companies?
The OEM Continentals wear pretty well, but seriously lack traction in snow/ice/sand/mud.
The Michelin LTX MS2's I'm using will easily go 100k miles, and provide excellent traction
in all of the above low traction categories. I get better mileage with the MS2's as well.
(approx. 1 mpg better).
Roger
__________________
2014 Sprinter 516 series (3500 DRW) 170"/4325 mm wb Hi Top Short Back
OM-651 I4 2.143 liter two stage turbo charged with 36.9 PSIA MAP Limit Valve
7 Speed 7G-Tronic, manually shiftable, automatic transmission.
Suspension Seats, Active Safety Package +, Parktronic, OEM Hitch/wiring
OEM back up camera, Bi Xenon light package, fog lamps, headlight washers.
Had 2006 T1N 3500/158|2010 NCV3 519/3500/144|2011 & 2012 NCV3 519/3500 170
sailquik is offline   Reply With Quote
Old 07-23-2012, 05:05 AM   #30
CJPJ
2008 3500 170"ext. 3.0 V6
 
CJPJ's Avatar
 
Join Date: May 2010
Location: Contra Costa California, Douglas County, Oregon
Posts: 3,907
Thanks: 3,861
Thanked 2,009 Times in 1,315 Posts
Default Re: incorrect pillar label (tire size and pressure)

....... At the time I posted those figures 02/18/12,..Michelin is the tire manufacture, and the LTX M/S2 was the tire choice. Those figures:....... I believe....... were from a Michelin pamphlet, I got at Costco.
BTW... I found Snow chains that fit tight clearance duellies!
CJPJ is online now   Reply With Quote

Tags
conversion, roadtrek, tires

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT. The time now is 08:25 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.