24 Valve Engine and Drivetrain Discuss the 24 Valve engine and drivetrain here. No non-drivetrain discussions please. NO HIGH PERFORMANCE DISCUSSION!

315's Beware

Thread Tools
 
Search this Thread
 
Old 02-10-2009, 10:32 PM
  #1  
Registered User
Thread Starter
 
tmansfield33's Avatar
 
Join Date: Sep 2006
Location: Mill Creek, WA
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
315's Beware

I just put on a set of H2 wheels with the 315's. It sure does look sweet, but it knocked my mileage down about 2mpg. In my mind, 10% is a fine price to pay for the way it looks now. Just a warning though...nothing comes for free.
Old 02-11-2009, 12:35 AM
  #2  
Registered User
 
cody_d's Avatar
 
Join Date: Mar 2008
Location: Utah
Posts: 153
Likes: 0
Received 0 Likes on 0 Posts
what gears do you have?
Old 02-11-2009, 12:44 AM
  #3  
Registered User
 
96WhiteBuffalo's Avatar
 
Join Date: Jan 2009
Posts: 88
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by tmansfield33
I just put on a set of H2 wheels with the 315's. It sure does look sweet, but it knocked my mileage down about 2mpg.
Did you recalculate for the bigger tires?
Old 02-11-2009, 08:30 AM
  #4  
Registered User
 
RowJ's Avatar
 
Join Date: Apr 2004
Location: Texas/Oklahoma Border
Posts: 8,234
Likes: 0
Received 1 Like on 1 Post
http://www.sjdsm.com/tech/tire_size.htm

RJ
Old 02-11-2009, 09:39 AM
  #5  
Registered User
 
sheriffav8r's Avatar
 
Join Date: Sep 2007
Location: Cape Coral, FL
Posts: 1,101
Likes: 0
Received 1 Like on 1 Post
Yeah, but now I can run over slow people in small cars hogging the left lane.... Seriously, I think the 315's I have are the biggest I will put on my truck. Still handles okay, but I can tell that I would have to put a lot more effort to keep it in my lane if the tires were any bigger....
Old 02-11-2009, 09:45 AM
  #6  
Registered User
 
DNRCustoms's Avatar
 
Join Date: Dec 2007
Location: Richmond, MI
Posts: 1,341
Likes: 0
Received 1 Like on 1 Post
315 Bfg = D.w
Old 02-11-2009, 09:45 AM
  #7  
Registered User
 
Mechanos's Avatar
 
Join Date: Jan 2004
Location: Kansas City, MO
Posts: 843
Likes: 0
Received 1 Like on 1 Post
Did you have the PCM reflashed to the new tire size?
Old 02-11-2009, 09:49 AM
  #8  
Registered User
 
06silvermega's Avatar
 
Join Date: Jan 2009
Location: Omaha, Ne
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by DNRCustoms
315 Bfg = D.w
= death wooble? I don't have death wobble with my 315's. Where did you come up with that?
Old 02-11-2009, 06:11 PM
  #9  
Registered User
 
notched's Avatar
 
Join Date: Jun 2007
Location: Medford, OR
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
I'm running 315 Coopers, and I have no issues. The truck has a leveling kit on the front and the 315s sure look good!!
Old 02-12-2009, 01:09 AM
  #10  
Registered User
Thread Starter
 
tmansfield33's Avatar
 
Join Date: Sep 2006
Location: Mill Creek, WA
Posts: 32
Likes: 0
Received 0 Likes on 0 Posts
It is a little more work to keep it in the lane--that could be due to the leveling kit though. I did the ol' cell phone calculator and tripometer method for coming up with my number. I've dropped from around 20mpg on the highway to 17.9 on my most recent traffic-free trip from Pasadena to Laguna Beach. I put some Pro-Comp ES9000's on there too, and with the addition of the bigger tires, it rides a lot better. In my book that's two (looks and ride) for and one against (mpg) the new tires. I'm happy with it.

I have the 3.55 gears, I'm sure if I had 4.10s the mileage would have gotten better.
Old 02-13-2009, 08:45 PM
  #11  
Registered User
 
can17's Avatar
 
Join Date: May 2006
Location: Tennessee
Posts: 140
Likes: 0
Received 0 Likes on 0 Posts
I have 4.10s and went from 295's to 315's and my mileage is ~ .5 mpg less with the 315s. (I did correct my odometer reading with both sizes, btw)
I think the actual tire itself has alot to do with mileage results. For example, the tires in my sig weigh 76#s apiece, while a BFG AT in the same size weighs 67#s.
Old 02-14-2009, 11:03 AM
  #12  
Registered User
 
DMcPherson's Avatar
 
Join Date: Jun 2006
Location: ct
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
I have the same combo, itonly affected mileage around town. you have to add he mileage lost from not having corrected the speedo. roughly 5 miles for every 60. if im doing my math correctly. I also thought mileage wouldbe better on teh highway being lower rpm, but it likes to be around 1900 -2000 rpm and with 3.54's your moving
Old 02-14-2009, 11:56 AM
  #13  
Chapter President
 
dodgeguy71's Avatar
 
Join Date: Mar 2006
Location: Near Mt. Pleasant, Tennessee
Posts: 1,327
Likes: 0
Received 0 Likes on 0 Posts
I think what DNR Customs was trying to say is that 315's equal death wobble. Perhaps not on the better design 03 and up since us 2nd gen'rs can upgrade to the 3rd gen trac bar. I think his comment may have been more toward us 2nd gen'rs putting on 315's as it is already weak in the front and adding 65-75lbs of tire out there will only increase your percentage rate of having the death wobble all to yourself.
Old 02-16-2009, 04:43 AM
  #14  
Registered User
 
Lurch519's Avatar
 
Join Date: Jun 2003
Location: Youngtown, Arizona
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
I've had 315's on my truck for a little over 100,000 miles (161,333 on the clock now) and have never had a problem with the front end shaking. My track arm is pretty much worn out, but no wierd handling problems. I've got a 2 inch leveler on the front too.
Old 02-16-2009, 06:43 AM
  #15  
Registered User
 
gwhammy's Avatar
 
Join Date: Dec 2003
Location: NE,Missouri
Posts: 733
Likes: 0
Received 0 Likes on 0 Posts
My speedo is off about 10 percent with the 315's according to the garmin gps. That would make the milage you lost back up if it's correct for your truck.


Quick Reply: 315's Beware



All times are GMT -5. The time now is 07:40 PM.