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MarkWard Samba Member
Joined: February 09, 2005 Posts: 17007 Location: Retired South Florida
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Posted: Wed Dec 24, 2014 5:49 am Post subject: |
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Kam, I am replacing the tires on my 2wd camper. GW 16 rims. I was reading your tire thread and could not quite figure out where the 9% penalty comes from? It is not the math I don't understand, but where does that actual value come from? It seems you apply it to even the stock 14's that came on the Vanagons from the factory. Thank you. mark _________________ ☮️ |
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Randy in Maine Samba Member
Joined: August 03, 2003 Posts: 34890 Location: The Beach
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Posted: Fri Dec 26, 2014 4:09 pm Post subject: |
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It is a US Federal DOT requirement from about the mid 90's I would guess....
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=195
P-metric tires used on passenger cars and station wagons are rated to carry 100% of the load indicated on the tire's sidewall (or listed for the tire in industry load/inflation charts). However, if the same P-metric tires are used on light trucks, (pickup trucks and sport utility vehicles for example), their carrying capacity is reduced to 91% of the load indicated on the tire's sidewall. This reduction in load results in causing light truck vehicle manufacturers to select proportionately larger P-metric sized tires for their vehicles to help offset the forces and loads resulting from a light truck's higher center of gravity and increased possibility of being occasionally "overloaded."
If you need more info, I can link you to the Federal DOT site and actual rule... |
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MarkWard Samba Member
Joined: February 09, 2005 Posts: 17007 Location: Retired South Florida
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Posted: Mon Dec 29, 2014 8:40 am Post subject: |
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Randy, thank you for the link. I think what confused me is the Kamz was applying the 9% penalty to the original vanagon 14" tires which were not passenger tires if I recall. I remember them having reinforced sidewalls and that is why they are harder to replace as a result. I will be looking at LT tires if I can find the correct size. mark _________________ ☮️ |
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davevickery Samba Member
Joined: July 16, 2005 Posts: 2887 Location: Fort Collins, CO
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Posted: Mon Dec 29, 2014 2:45 pm Post subject: |
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Not to get lost in the details, it is worth a reminder that "What Tires Fit" can be found on page 1.
That link was not the ruling, just someone's rephrasing and adding their opinon about why. See FMVSS 571.110. S4.2.2.2.
The definition from the actual ruling: Passenger car tire means a tire intended for use on passenger cars, multipurpose passenger vehicles, and trucks, that have a gross vehicle weight rating (GVWR) of 10,000 pounds or less. While a Light truck (LT) tire means a tire designated by its manufacturer as primarily intended for use on lightweight trucks or multipurpose passenger vehicles. Note the wording just says primarily intended for.
Who knows if the Michelin intended the MXL for use only on trucks and MPVs, but I kind of doubt it. The rule didn't exist back then so why would they have excluded cars in their intended market. So even thought they were reinforced they would still be derated once the rule came into effect.
Today they make plenty of standard load tires primarily intended for use on trucks and SUVs, like the General Grabber AT or the Yokohama Geolander AT which is not a C load tire in most sizes. So it seems that even some of the standard load tires do not need to be downrated and of course C/D load tires don't.
From a little digging, the new rule for the down rating and a bunch of others came out of the TREAD act of 2000. The derating rule (S4.2.2.2) wasn't finalized until June 2003 and appears not have been mandatory until 2007.
EFFECTIVE DATE
NOTES: 1. At 68 FR 38147, June 26, 2003,
§ 571.110 was amended by revis-
ing S2, S4.1, S4.2.1, S4.2.2, S4.4.1(a), and table
1 following S4.4.1(b), by adding S4.2.1.1,
S4.2.1.2, S4.2.2.1, S4.2.2.2...effective June 1, 2007"
"S4.2.2.2 When passenger car tires are
installed on an MPV, truck, bus, or
trailer, each tire’s load rating is re-
duced by dividing it by 1.10 before de-
termining, under S4.2.2.1, the sum of
the maximum load ratings of the tires
fitted to an axle."
"S4.2.2.1 Except as provided in
S4.2.2.2, the sum of the maximum load
ratings of the tires fitted to an axle
shall not be less than the GAWR of the
axle system as specified on the vehi-
cle’s certification label required by 49
CFR part 567. If the certification label
shows more than one GAWR for the
axle system, the sum shall be not less
than the GAWR corresponding to the
size designation of the tires fitted to
the axle. "
http://www.gpo.gov/fdsys/granule/CFR-2011-title49-vol6/CFR-2011-title49-vol6-sec571-110
http://www.gpo.gov/fdsys/pkg/CFR-2005-title49-vol6/pdf/CFR-2005-title49-vol6-sec571-110.pdf
http://www.nhtsa.gov/cars/rules/rulings/TREAD/NPRM/Index.html#sec1 |
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kamzcab86 Samba Moderator
Joined: July 26, 2008 Posts: 7892 Location: Arizona
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Posted: Wed Dec 31, 2014 11:16 am Post subject: |
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rsxsr wrote: |
Kam, I am replacing the tires on my 2wd camper. GW 16 rims. I was reading your tire thread and could not quite figure out where the 9% penalty comes from? It is not the math I don't understand, but where does that actual value come from? It seems you apply it to even the stock 14's that came on the Vanagons from the factory. Thank you. mark
...
Randy, thank you for the link. I think what confused me is the Kamz was applying the 9% penalty to the original vanagon 14" tires which were not passenger tires if I recall. I remember them having reinforced sidewalls and that is why they are harder to replace as a result. I will be looking at LT tires if I can find the correct size. mark |
Keep in mind, that post #1 is merely a culmination of numerous tire threads found here on The Samba, along with currently available tires that are deemed appropriate for use on a Vanagon/EuroVan. I am no tire expert; I was merely attempting to put tire info in one spot for folks to easily find.
As for the 9% rule, it is only applied to one tire used by Volkswagen, which is the Michelin MXL, a reinforced passenger car tire (all other tires used were light truck C- or D-load tires). While the rule did not exist back when Vanagons were new, it should, in theory, be applied now for safety's sake. _________________ ~Kamz
1986 Cabriolet: www.Cabby-Info.com
1990 Vanagon Westfalia: Old Blue's Blog
2016 Golf GTI S
"Real knowledge is to know the extent of one's ignorance." - 孔子 |
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luVWagn Samba Member
Joined: February 21, 2008 Posts: 1340 Location: Snoqualmie (WA)
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flomulgator Samba Member
Joined: March 07, 2013 Posts: 950 Location: Leavenworth, WA
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Posted: Mon Jan 05, 2015 9:11 am Post subject: |
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So I got 3 questions/notes:
1) 4WD has three original tire sizes listed, and so does my door. How do I determine my original tire size when they're long gone? It seems that info is needed to correctly figure out PSI in page 1.
2) I made an assumption that the original PSI was 36/43. I worked through the procedures and the links described in the sticky, and for my Nokian WR C Van Load Range 105 arrived at essentially the same PSI (<35 F, 43 R). Is this technically correct?
3) Toyo load inflation table link on frontpage is broken. _________________ She's built like a steakhouse, but she handles like a bistro! |
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dobryan Samba Member
Joined: March 24, 2006 Posts: 16473 Location: Brookeville, MD
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flomulgator Samba Member
Joined: March 07, 2013 Posts: 950 Location: Leavenworth, WA
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dobryan Samba Member
Joined: March 24, 2006 Posts: 16473 Location: Brookeville, MD
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flomulgator Samba Member
Joined: March 07, 2013 Posts: 950 Location: Leavenworth, WA
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dobryan Samba Member
Joined: March 24, 2006 Posts: 16473 Location: Brookeville, MD
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flomulgator Samba Member
Joined: March 07, 2013 Posts: 950 Location: Leavenworth, WA
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Posted: Mon Jan 05, 2015 12:55 pm Post subject: |
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Sorry I didn't read that far. Contact Nokian North America directly and ask where you can find them, because they are listed as a current tire size being produced. I have had previous success communicating with them via email.
http://www.nokiantires.com/company/contact/ _________________ She's built like a steakhouse, but she handles like a bistro! |
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dobryan Samba Member
Joined: March 24, 2006 Posts: 16473 Location: Brookeville, MD
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Randy in Maine Samba Member
Joined: August 03, 2003 Posts: 34890 Location: The Beach
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Posted: Mon Jan 05, 2015 1:39 pm Post subject: |
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The Nokian guy by me says they no longer make the WR C Van tire.
Have you tried the Haka CR3? |
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dobryan Samba Member
Joined: March 24, 2006 Posts: 16473 Location: Brookeville, MD
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Team WorldTour Samba Member
Joined: September 02, 2010 Posts: 2426 Location: Der Vaterland
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flomulgator Samba Member
Joined: March 07, 2013 Posts: 950 Location: Leavenworth, WA
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Posted: Wed Jan 21, 2015 4:45 pm Post subject: |
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flomulgator wrote: |
So I got 3 questions/notes:
1) 4WD has three original tire sizes listed, and so does my door. How do I determine my original tire size when they're long gone? It seems that info is needed to correctly figure out PSI in page 1.
2) I made an assumption that the original PSI was 36/43. I worked through the procedures and the links described in the sticky, and for my Nokian WR C Van Load Range 105 arrived at essentially the same PSI (<35 F, 43 R). Is this technically correct?
3) Toyo load inflation table link on frontpage is broken. |
Anyone want to take a shot at my questions? _________________ She's built like a steakhouse, but she handles like a bistro! |
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Jake de Villiers Samba Member
Joined: October 24, 2007 Posts: 5911 Location: Tsawwassen, BC
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Posted: Wed Jan 21, 2015 7:32 pm Post subject: |
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flomulgator wrote: |
flomulgator wrote: |
So I got 3 questions/notes:
1) 4WD has three original tire sizes listed, and so does my door. How do I determine my original tire size when they're long gone? It seems that info is needed to correctly figure out PSI in page 1.
2) I made an assumption that the original PSI was 36/43. I worked through the procedures and the links described in the sticky, and for my Nokian WR C Van Load Range 105 arrived at essentially the same PSI (<35 F, 43 R). Is this technically correct?
3) Toyo load inflation table link on frontpage is broken. |
Anyone want to take a shot at my questions? |
What size are the tires and what year and configuration is your van? _________________ '84 Vanagon GL 1.9 WBX
'86 Westy Weekender Poptop/2.5 Subaru/5 Speed Posi/Audi Front Brakes/16 x 7 Mercedes Wheels - answers to 'Dixie'
@jakedevilliersmusic1
http://sites.google.com/site/subyjake/mydixiedarlin%27
www.crescentbeachguitar.com
www.thebassspa.com |
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flomulgator Samba Member
Joined: March 07, 2013 Posts: 950 Location: Leavenworth, WA
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Posted: Wed Jan 21, 2015 8:17 pm Post subject: |
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215/65-16
1987 Syncro tintop originally, now a Westy. _________________ She's built like a steakhouse, but she handles like a bistro! |
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