You're going to worry over 20 + Lbs. difference in tire weight related to mpg's.
Get real
| LOST JEEPS http://www.lostjeeps.com/forum/phpBB3/ |
|
| 245/70/16 mpg question – weight vs. width http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=8&t=25544 |
Page 1 of 1 |
| Author: | scoobysnax [ Wed Oct 17, 2007 4:41 pm ] |
| Post subject: | 245/70/16 mpg question – weight vs. width |
My goal is to find a tire with the greatest ability off-road without greatly sacrificing on road performance or MPG. I don’t want a MT tire b/c they will drop my mpg’s too much. So I’m looking for an AT tire with a good mix of everything. Most of the driving I do is dry or wet roads and in the NE some snow in the winter time. The main wheeling I will be doing will be dirt, dirt/loose rock, snow, sand and some mud here and there. I would like to go to 245 width for increased floatation on sand, better road grip, slight increase in ground clearance and overall better looks. After reading a lot of posts I don’t think I should/will have any rubbing issues and if it only happens at full lock I can deal with that. Currently I have 235/70/16 Wrangler SR-A’s. I bought the Jeep used but I think they are the stock tires (I have about 32,000 miles on them if they are stock.) Right now I am looking at the 245/70/16 Bridgestone Dueler A/T Revo’s. The runner up are the 245/70/16 Goodyear Wrangler Silent Armor. My question is will I notice a decrease in mpg and if so how much? Would it just be a negligible difference with this particular tire and a more significant difference with a heavier tire? My current Wranglers are listed @ 32lbs each and the tread pattered is more of a highway rib style. The Revo’s are listed @ 36lbs each and their tread pattern is a good mix of highway ribbed and offset (somewhat) aggressive tread. The Silent Armor is listed @ 38lbs and also a mix of highway ribbed and offset (somewhat) aggressive tread. What is the bigger factor? The tread pattern and extra width affecting the rolling resistance? Or the extra weight and rotating mass of a heavier tire (in this case 4lbs each or 20lbs total (I’m only getting 4, my spare has never been used.) If it’s the weight I’ll probably pick the lighter tire. If it’s the width I may just stay with a 235/70/16 size. As it is, I average anywhere from 20 – 24mpg in just highway driving and anything from 13-16mpg in true (NYC) city driving. Will I feel a greater mpg loss in city driving due to the constant adjustment to the rotation of the tire and the extra mass or more on the highway where the extra rotation mass could have a multiplying effect at speeds? Yes I know I didn’t buy the Jeep for it’s great mileage but I also don’t want (and can’t afford at these prices) to decrease the already poor mpg. Any thoughts are appreciated. |
|
| Author: | Pote [ Wed Oct 17, 2007 5:42 pm ] |
| Post subject: | |
http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=25066 another with about the same kind of answers: http://www.lostjeeps.com/forum/phpBB3/vie ... ire+weight |
|
| Author: | KJ04 [ Wed Oct 17, 2007 6:40 pm ] |
| Post subject: | |
You're going to worry over 20 + Lbs. difference in tire weight related to mpg's. Get real
|
|
| Author: | Bill.Barg [ Wed Oct 17, 2007 7:00 pm ] |
| Post subject: | |
KJO4..... 20 lb static weight is no big deal, you are right... but if you are spinning up extra weight in stop and go traffic , it is a big deal. It takes power to spin up a tire. Scoobysnax is right on the money, IMHO. |
|
| Author: | tjkj2002 [ Wed Oct 17, 2007 7:19 pm ] |
| Post subject: | |
I remember reading somewhere that if you add 1lb rotating wieght it's like adding 10lbs static wieght.So a tire that wieghs 10lbs heavier then the stock one's then you are theoretically adding 100lbs extra wieght per tire,so a total of 400lbs added "static" wieght,that's a pretty big deal.Don't quate me on those figures,I just remember that from long time ago in high school auto class. |
|
| Author: | scoobysnax [ Wed Oct 17, 2007 7:50 pm ] |
| Post subject: | |
KJ04 - I used to ride a bike, (Suzuki Bandit 1200, almost nothing stock, miss it) and learned a lot about rotating mass in an effort to understand how my bike would react in various situations. Here’s a great way to understand everything: Take the front wheel off a bicycle. Hold the hub in each hand and have someone else spin the wheel for you (or spin it with one hand and try to grab it again but watch out for your fingers in the spokes when you try to grab it again.) Now that you’ve got it spinning, try and turn the wheel to the left or right without letting it tilt the side. You won’t be able to do it even thought the wheel is less than 10lbs. As you turn the wheel to the left it will want turn pivot in the opposite direction usually at a 45 degree angle from an upright position. This is also the reason behind counter steering on a motorcycle to a turn the bike but that’s another topic entirely. Now if you have a road bike and a Mt. Bike do it with each bike’s wheel and I’m sure you’ll find that it easier with the lighter road wheel. So yup, 4 lbs extra on a wheel or 10-15 extra on a wheel makes a big difference. It’s also the same reason they tell you to upgrade your brakes and steering pump when you put larger wheels on your rig. |
|
| Page 1 of 1 | All times are UTC - 5 hours [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|