DODGE RAM FORUM - Ram Forums and Owners Club! - Dodge Truck Forum

Go Back   DODGE RAM FORUM - Ram Forums and Owners Club! - Dodge Truck Forum > Dodge Ram Forum - Mod Zone - Custom Dodge Ram Mods - Dodge Ram Performance > Custom Dodge Ram Performance Mods - Engine - 4.7 Liter V8


Notices

Custom Dodge Ram Performance Mods - Engine - 4.7 Liter V8 Discuss modifying your Dodge Ram with Performance Parts and Accessories!
Factory Spec: 4.7-liter V8 engine - 310 horsepower, 330 lb-ft of torque.


Latest Vendor News
AutoAnything
Addictive Desert Designs!
United Radio
Bayou Goat Mounts

View Poll Results: Are you happy with your 4.7L V8?
Love my 4.7 179 42.32%
Kind of wish I went with the 5.7 121 28.61%
REALLY wish I went with the 5.7 93 21.99%
I'm not picky.. 30 7.09%
Voters: 423. You may not vote on this poll

Reply
 
Thread Tools
  #81  
Old 10-03-2011, 03:12 PM
snrusnak's Avatar
snrusnak snrusnak is offline
Dodge Ram Forum Senior Member!
 
Join Date: Jan 2011
Location: Orlando
Age: 27
Posts: 13,386
Gender: Male
Vehicle: 2010 Dodge Ram 1500
Trim Level: SLT
Color: White
Engine: 2008-20?? 287ci (4.7L) PowerTech V8 310hp 330lb/ft
Rep Power: 12
Rep:1385
snrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud of
Default

Yeah that's basically a 33.5-34" diameter tire, not toooo huge, although also very wide, definitely some mpg loss there. You'd gain some back probably with 3.92's or 4.10's...but that's another topic...

I'd try the dealership and tell them what happened and maybe they'll have an answer for you...Seems like the problem started with them...
__________________
Sean

Breathing in and out is good enough for me.
Reply With Quote
Sponsored links
  #82  
Old 10-03-2011, 03:17 PM
DirtyD's Avatar
DirtyD DirtyD is offline
Dodge Ram Forum Senior Member!
 
Join Date: Sep 2011
Location: Afghan :\
Age: 30
Posts: 181
Gender: Male
Vehicle: 05 QC 1500 ~ Carolina Edition
Color: Black
Engine: 2002-2007 287ci (4.7L) PowerTech V8 235hp 295lb/ft
Rep Power: 0
Rep:45
DirtyD is on a distinguished road
Default

idk about those guys.. they try to tell me that with my tires my speedo wouldnt be that far off and that it doesnt matter how fast u go, it will stay the same off.. when i know the faster you go the more off it is.
__________________
Truck - 05 QC 1500 4x4 ~ Carolina Edition ~ Stock sitting on LT305/70R17 Terra Grappler

Toy - Golf Cart - F/R samurai axles, 280cc engine, hydro steering, 31x15 Tires, 3 link F/R
Reply With Quote
  #83  
Old 10-03-2011, 03:28 PM
snrusnak's Avatar
snrusnak snrusnak is offline
Dodge Ram Forum Senior Member!
 
Join Date: Jan 2011
Location: Orlando
Age: 27
Posts: 13,386
Gender: Male
Vehicle: 2010 Dodge Ram 1500
Trim Level: SLT
Color: White
Engine: 2008-20?? 287ci (4.7L) PowerTech V8 310hp 330lb/ft
Rep Power: 12
Rep:1385
snrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud of
Default

what size were your stock tires? and yeah you're right it's off by a percentage, so faster makes it thrown off more.
__________________
Sean

Breathing in and out is good enough for me.
Reply With Quote
  #84  
Old 10-03-2011, 03:47 PM
DirtyD's Avatar
DirtyD DirtyD is offline
Dodge Ram Forum Senior Member!
 
Join Date: Sep 2011
Location: Afghan :\
Age: 30
Posts: 181
Gender: Male
Vehicle: 05 QC 1500 ~ Carolina Edition
Color: Black
Engine: 2002-2007 287ci (4.7L) PowerTech V8 235hp 295lb/ft
Rep Power: 0
Rep:45
DirtyD is on a distinguished road
Default

stock tire size is 245/70R17
__________________
Truck - 05 QC 1500 4x4 ~ Carolina Edition ~ Stock sitting on LT305/70R17 Terra Grappler

Toy - Golf Cart - F/R samurai axles, 280cc engine, hydro steering, 31x15 Tires, 3 link F/R
Reply With Quote
  #85  
Old 10-03-2011, 04:00 PM
snrusnak's Avatar
snrusnak snrusnak is offline
Dodge Ram Forum Senior Member!
 
Join Date: Jan 2011
Location: Orlando
Age: 27
Posts: 13,386
Gender: Male
Vehicle: 2010 Dodge Ram 1500
Trim Level: SLT
Color: White
Engine: 2008-20?? 287ci (4.7L) PowerTech V8 310hp 330lb/ft
Rep Power: 12
Rep:1385
snrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud of
Default

If my math's correct:

33.5"/30.5" = ~109.8% so at 70 mph 70(1.098)=6.86mph difference

That's not that much....I'd see if the dealer can set it back to what it was so you can see if you mpg improves... keep in mind your odometer would be off though...
__________________
Sean

Breathing in and out is good enough for me.
Reply With Quote
  #86  
Old 10-03-2011, 04:06 PM
DirtyD's Avatar
DirtyD DirtyD is offline
Dodge Ram Forum Senior Member!
 
Join Date: Sep 2011
Location: Afghan :\
Age: 30
Posts: 181
Gender: Male
Vehicle: 05 QC 1500 ~ Carolina Edition
Color: Black
Engine: 2002-2007 287ci (4.7L) PowerTech V8 235hp 295lb/ft
Rep Power: 0
Rep:45
DirtyD is on a distinguished road
Default

my wife got pulled over doing 58 the cop said she was doing 70
__________________
Truck - 05 QC 1500 4x4 ~ Carolina Edition ~ Stock sitting on LT305/70R17 Terra Grappler

Toy - Golf Cart - F/R samurai axles, 280cc engine, hydro steering, 31x15 Tires, 3 link F/R
Reply With Quote
  #87  
Old 10-03-2011, 04:12 PM
snrusnak's Avatar
snrusnak snrusnak is offline
Dodge Ram Forum Senior Member!
 
Join Date: Jan 2011
Location: Orlando
Age: 27
Posts: 13,386
Gender: Male
Vehicle: 2010 Dodge Ram 1500
Trim Level: SLT
Color: White
Engine: 2008-20?? 287ci (4.7L) PowerTech V8 310hp 330lb/ft
Rep Power: 12
Rep:1385
snrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud ofsnrusnak has much to be proud of
Default

should be like 64mph if the speedo said 58mph...
__________________
Sean

Breathing in and out is good enough for me.
Reply With Quote
  #88  
Old 10-03-2011, 09:07 PM
starquestbd22's Avatar
starquestbd22 starquestbd22 is offline
Dodge Ram Forum Senior Member!
 
Join Date: Jan 2011
Location: NC
Age: 32
Posts: 2,639
Gender: Male
Vehicle: 2004 Dodge Ram 1500 4X4
Trim Level: Sport quad cab
Color: Bright Silver Metallic
Engine: 2003-2008 345ci (5.7L) Hemi V8 345hp 375lb/ft
Rep Power: 5
Rep:360
starquestbd22 is just really nicestarquestbd22 is just really nicestarquestbd22 is just really nicestarquestbd22 is just really nice
Default

This site gives a great comparison. Just plug in the two tires sizes.
http://www.1010tires.com/TireSizeCalculator.asp

You were very close snrusnak. His speedo is actually off by 10.84% and reading too slow, of course. Your calculation was off by just a hair because his current tire is actually 33.81 inches tall. That still doesn't make up for the alleged 70 mph reading as 58 mph though. Is she certain when he clocked her? Maybe a bad clock? Who knows? If she didn't get a ticket I wouldnt worry about that too much because there are a lot of variables with radar that could have caused that. With that percentage (and before the dealership "fixed" it) if your speedo said 55 mph you would actually be going about 61 mph. Speedo 60 mph would actually be about 66.5 mph. And speedo 70 mph actually about 77.6 mph.

As for your gas mileage.....I don't know if the digital reading uses a distance reading (such as from your speed sensor) to calculate the gas mileage or not but if it does then it makes sense for the bigger tires to alter the calculated mileage as well. Not including the dealer "fix" your truck is actually traveling 1.10 miles for every mile that it thinks it traveled. So you would be getting an extra tenth of a mile for every one of those gallons that your truck is reporting as miles per gallon. What's odd is that if your were getting 10-11 before the dealer fix and now you are getting 8-9.....that's an almost exact 10% reported loss. The weird part is that you should have observed that reported loss when you put on the bigger tires, not when the dealer "fixed" it, lol.

Here's a theory...once again, not knowing how the dealer "fixes" the reading (but assuming they alter the tire diameter through new input to the PCM just like a programmer) is it possible they went in wrong direction and effectively made your speedo off by nearly twice as much? That would come closer to explaining the radar clock (70 mph x 0.2168 (which is your tire size difference doubled) = 15.1 mph off which would read about 55 on your speedo. It would also explain why your reported mileage dropped after the "fix". Once again, this is all assuming the truck uses the measured speed to calculate the mileage. If not, disregard the last two paragraphs, lol.

Simple solution...calculate it by hand. Your calculation will always vary from the display but if you get a hand reading that is higher than your display reading then you can pretty much guarantee the display is wrong for some reason. Good luck!!
__________________
06-08 chrome clads w/33" Cooper Discoverer H/T Plus, Mopar tailgate spoiler, debadged door trim & tailgate emblems, 13" antenna, LED dome & maps, Magnaflow 22" SI/DO, 18% tint, "HEMI" hood spears, VHT tinted tails & third brake light, Lamin-x optic blue fogs, leveled w/McGaughys 2" drop shackles.
Reply With Quote
  #89  
Old 10-03-2011, 09:13 PM
DirtyD's Avatar
DirtyD DirtyD is offline
Dodge Ram Forum Senior Member!
 
Join Date: Sep 2011
Location: Afghan :\
Age: 30
Posts: 181
Gender: Male
Vehicle: 05 QC 1500 ~ Carolina Edition
Color: Black
Engine: 2002-2007 287ci (4.7L) PowerTech V8 235hp 295lb/ft
Rep Power: 0
Rep:45
DirtyD is on a distinguished road
Default

Ya she said she was sure, and she did get a ticket, that is when i went and had them "fix" it. i also bought the truck with those tires on it. the dealership said they set the tire size in the PCM to as close as they could to what was on my truck. when i get the money i am getting a programer so i can go in and set the tires, and other stuff.
__________________
Truck - 05 QC 1500 4x4 ~ Carolina Edition ~ Stock sitting on LT305/70R17 Terra Grappler

Toy - Golf Cart - F/R samurai axles, 280cc engine, hydro steering, 31x15 Tires, 3 link F/R
Reply With Quote
  #90  
Old 10-03-2011, 09:45 PM
starquestbd22's Avatar
starquestbd22 starquestbd22 is offline
Dodge Ram Forum Senior Member!
 
Join Date: Jan 2011
Location: NC
Age: 32
Posts: 2,639
Gender: Male
Vehicle: 2004 Dodge Ram 1500 4X4
Trim Level: Sport quad cab
Color: Bright Silver Metallic
Engine: 2003-2008 345ci (5.7L) Hemi V8 345hp 375lb/ft
Rep Power: 5
Rep:360
starquestbd22 is just really nicestarquestbd22 is just really nicestarquestbd22 is just really nicestarquestbd22 is just really nice
Default

Ahhhhh, so she got clocked before they "fixed" it. In that case, just like snrusnak said...a speedo reading of 58 mph should be about 64.2 mph. Can't explain that other than maybe the radar was off or more likely the officer was mistaken or made an improper clock. Sadly, not much you can do about that usually. Not sure about your area but here in NC your best bet would be to explain the larger tires throwing off the speedo and ask for a reduction.

That does still make sense about the dealer throwing your speedo further off though. Take your readings before the dealer fix and add the 10.84% back and your truck would be getting 11-13.3 mpg with stock tires. That is still pretty crappy but closer to what you would expect. My 2006 4.7 quad cab auto 4x4 with the 3.92 gears averages about 13-14 and maybe 15.5 on the highway if I keep it in the sweet spot around 70.
__________________
06-08 chrome clads w/33" Cooper Discoverer H/T Plus, Mopar tailgate spoiler, debadged door trim & tailgate emblems, 13" antenna, LED dome & maps, Magnaflow 22" SI/DO, 18% tint, "HEMI" hood spears, VHT tinted tails & third brake light, Lamin-x optic blue fogs, leveled w/McGaughys 2" drop shackles.
Reply With Quote
Reply

Bookmarks

Thread Tools

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Happy Belated Birthday to our Nick!!!! iRESQu Off Topic Discussion 13 10-07-2010 09:57 AM
Another happy owner Luger Newbie Checkin! 17 09-24-2009 10:02 AM
Happy Birthday, Stacy aka BlueJet DaveDees Off Topic Discussion 24 01-27-2009 01:34 AM
Happy Birthday 300Addict cowboytruckn Off Topic Discussion 9 08-05-2008 04:51 PM


Advertisement






All times are GMT -4. The time now is 04:52 AM.


= Copyright RamForumZ.com a Gigathreads.com Network Site =Ad Management by RedTyger
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
vB.Sponsors


=Gigathreads Network=
CLUBS MOPAR NATION DSM GPMM MAMM JAM
DIESEL Diesel Forum      
CHEVY Chevy Camaro Forum Chevy Volt Forum    
CHRYSLER Chrysler 300C Forum      
DODGE Dodge Avenger Forum Dodge Caliber Forum Dodge Challenger Forum Dodge Charger Forum
  Dodge Circuit Forum Dodge Hornet Forum Dodge Magnum Forum Dodge Nitro Forum
  Dodge Ram Forum Dodge Dakota Forum Dodge Durango Forum Dodge Dart Forum
FORD Ford Raptor Forum Ford F150 Forum Ford F100 Forum  
JEEP Jeep Forum      
PONTIAC Pontiac G8 Forum      
SRT SRT Viper Forum SRT Cuda Forum