12 messages,
Last post on Apr 30, 2010 at 11:00 AM
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Chrysler Town & Country/Dodge Grand Caravan Forum.
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Chrysler Town and Country, Wheels, Van
#3 of 12 Re: What 16in Wheels and Snow Tires for 08 T&C LTD ? [xwesx]
by 356
Dec 29, 2009 (2:17 pm)
Thank You for the info . What size tires do you use ? The Turanza 225/65-17 diameter is 28.5in on my LTD and the Winterforce 225/70-16 is 28.4 in which is fine.
#4 of 12 Re: What 16in Wheels and Snow Tires for 08 T&C LTD ? [356]
by xwesx
Jan 04, 2010 (11:23 am)
I do not have winter tires on my DGC, but it has 15" wheels (1998) and, I think, uses P215/70R15. For that year, I believe that 15" steel wheels and 16" alloy wheels were standard. There are tire size calculators available that should help with the conversion; 2% is the generally accepted tolerance range for speedometer/odometer variance. As long as the rims clear the brake calipers and the tires are not too wide for the wheel wells & strut towers, you should be fine. Normally, a tire 10 mm larger or less will fit with no problem. So, if the stock tire is a 225, you can likely go with any tire size <=235, with the appropriate ratio to keep the diameter compatible with the speedometer tolerance, and be fine. On my Forester, the UGI's are 215/65R16 (mounted on a steel wheel), with the stock tires being 225/55R17 (mounted on an alloy).
#5 of 12 T & C "99 16 inch wheel to 17
by timbodey
Apr 26, 2010 (7:02 pm)
Am wanting to go to a 17in. wheel from stock size 16in. mfg. sticker reads 215/65 x 16 for this "99 Limited AWD. I tried a 16in. Jeep wheel , it has the same bolt pattern . I want to install Chrysler product alloy wheels . I like some of the wheels that are on the Dodge pick-ups. What wheels will work on the Town & Country ?
#6 of 12 Re: T & C "99 16 inch wheel to 17 [timbodey]
by srs_49
Apr 27, 2010 (4:06 am)
I don't have a specific answer for you, but just because the bolt hole pattern matches doesn't mean you should use that wheel on your van. An important parameter is the wheel offset, which is basically the difference between the center line of the wheel and the wheel bearing assembly. A wheel with the wrong offset could cause premature bearing wear and or failure, and also stresses other parts of the suspension.
#7 of 12 Re: T & C "99 16 inch wheel to 17 [srs_49]
by timbodey
Apr 27, 2010 (10:02 pm)
Thanks so much for the scoop on offsets, stresses and such. I'm a bit lacking in my research skills. I assumed I could get an answer from the parts man at the dealership. Did I ever feel like an ass. the guy didn't want to tell me anything unless I had a V I N number, and even then he said he couldn't be sure. In a nut shell I want 17" wheels to increase gas mileage. This has to be true, ? would go with 215/ 65 /17 vs. original 215/65/16. If this is too troublesome of a venture I may drop it and go with 215/70/16. Of course the speedometer would need to be recalibrated if I would even do that. I can get the rim offset factor but man that sure does seemtrue. A bit intense for my over simple brain but none the less true. I'm just a bit mind boggled and wondering if my best bet is to stay with original wheels and cheat by going up to a 70 instead of a 65 and if that is even opening a can of worms , worse. Who would be a knowledgeable person to ask on this question. The Chrysler parts man did not know and he didn't know if the bolt patern for a '2010 with 17" wheels was the same as a '99 with 16" wheels. thanks everyone
#8 of 12 Re: T & C "99 16 inch wheel to 17 [timbodey]
by capriracer
Apr 28, 2010 (2:54 am)
If you want better fuel economy, going from 16" to 17' is going the wrong direction.
But properly done a move as you suggested will not result in any speedometer error.
I suggest you go to Tire Rack's or Discount Tire's we site and do your reserach there. Those folks have measured the clearances and know what fits - and what doesn't. The folks at vehicle dealerships will not. They deal with replacing stock parts and can help you find the proper stock part for your car, but won't be able to help you with modifications. After all, they deal with tens of thousands of parts - by part number - for the vehicles their dealership sells - not the one-off modifed vehicle. You'll have to figure that part out yourself.
#9 of 12 Re: T & C "99 16 inch wheel to 17 [timbodey]
by xwesx
Apr 28, 2010 (11:07 am)
I need a little more clarification of your goal.... you want to increase fuel economy by doing what, increasing the circumference of the tire? In other words, you're thinking that with fewer revolutions per mile the engine will be running at slightly lower RPM and therefore use less fuel? If so, I'm not sure your results are going to net you gain, especially if it involves purchasing separate rims (and tires) and recalibrating your speedometer.
More effective may be to reduce rolling resistance of the tire by reducing the friction with the road. You can do this by going with a skinnier tire (say a 205 vs. a 215) or increasing the pressure in the tire.
The '99, as with all similar and more recent model years uses a 5x114.3 bolt pattern with a 71.5 mm center bore. For alloy rims, an offset of 40mm is, I believe, stock. The last I looked, Tire rack showed compatible rims with offsets of 35-40mm, but I never ended up putting alloys on my van and have stock steel rims (15") on it.
If the stock tire size is 215/65/R16, a smaller tire of 205/70/R16 will keep your calibration within 1.1%, a larger size of 215/70/R16 will put it off by 3%. If you go with 215/65/R17, you will be off by 3.6% and will likely increase your rolling mass because the rims are typically the heaviest part of the wheel/tire equation (which means more effort to get it moving and more stress on the suspension). But, that is the largest tire amongst these mentioned and it is only 1" larger in diameter than the stock tire, so any of them are going to physically fit on the van.
To summarize:
215/65/R16 rotations/mile: 747 calibration 100% speedometer reading at 60mph: 60
215/65/R17 rotations/mile: 720 calibration 96.4% speedometer reading at 60mph: 57.86
215/70/R16 rotations/mile: 724 calibration 97.0% speedometer reading at 60mph: 58.18
205/70/R16 rotations/mile: 739 calibration 98.9% speedometer reading at 60mph: 59.35
Now, if you want to go with a 17" rim for the sake of it, a 215/60/R17 tire is an excellent match, at 99.4% calibration.
#10 of 12 Re: T & C "99 16 inch wheel to 17 [xwesx]
by timbodey
Apr 29, 2010 (6:57 pm)
capriracer, xwesx ; thanks so much for your input. Am still unclear on a couple things. 1) what is the mass issue ? Is it the volume, (total area , size of the wheel ) , is it the weight of the wheel ? If stock size is 215/65 / 16 can 205/65 or 70/ 16 be safe ? I notice many SUV s have 17" or 18" wheels and 235/65 so I was wondering how much dammage can occur by going up one rim size 1" Seems like so many vehicles have such oversize tires that have been added after market. Your explanation of what I'm trying to accomplish is right on. But how is it that a larger rim size, with fewer rotations of the wheel does not improve gas mileage.? Is it as so say there is more mass which means ??? Of course there is the stress on other componets ...transmission, suspension,... and all this taken into account can amount to big trouble tha t is just not worth the bother and bottom line simply will not provide better gas mileage. thanks
#11 of 12 Re: T & C "99 16 inch wheel to 17 [timbodey]
by capriracer
Apr 30, 2010 (4:12 am)
Tim,
Going up in rim diameter, and making the proportional changes so that the load carrying capacity and overall diameter are the same - a process commonly called "Plus Sizing" - makes for a wider, heavier tire and rim assembly.
The loss in fuel economy is partially due to the extra weight that has to be accelerated (and slowed down) and partially because of the larger amount of tread rubber being deflected.
BTW, it is NOT the friction with the road surface that causes rolling resistance in a tire. It's a property called hysteresis. Another way to look at it is the internal friction of the rubber - and since most of the tire - particularly the part the is most involved with deflection - is the tread rubber, this dominates the rolling resistance picture. So more would be worse - meaning wider, deeper, etc.
But the single most dominant factor in rolling resistance is the rubber itself. You can get HUGE differences between tires that are otherwise identical just by changing the tread rubber. Unfortunately, this comes at the sacrifice of treadwear and/or traction.
Plus upsizing tends to put you into lower profiles - and this direction tends to go for traction by sacrificng treadwear (and RR).
So your best bet is to stick with the current size and search out tires that have the best combination of the properties you want.
#12 of 12 Re: T & C "99 16 inch wheel to 17 [timbodey]
by xwesx
Apr 30, 2010 (11:00 am)
But how is it that a larger rim size, with fewer rotations of the wheel does not improve gas mileage.?
After capriceracer's fantastic post, this is likely a moot point, but keep in mind that it is not the rim size that determines the number of rotations, it is the final diameter of the assembly, which is primarily determined by the tire size. For example, I can have a 17" rim and a 16" rim, with 225/55 tires on the first and 225/60 tires on the second, and the rotations per mile are nearly identical (754 versus 757). With a difference of 0.006%, do you really expect noticeable change in fuel economy if all other factors are equal? If I wanted to change the diameter significantly, I could simply put 225/75 tires on the 16" rims and I would have nine percent fewer rotations per mile (689 vs 757); the rim size remains the same - it is the tires that change the overall diameter.