New Higher GCWRs According to Allpar

[HBarlow]

Ram Chassis Cabs go higher-capacity at Allpar Chrysler, Dodge, and Jeep News

 

[Wertles]

That's better news. It just goes to show that Ram ratings just don't make sense. They will have an 2011. 5 3500 truck that is rated for more weight than their 2011 5500 C&C. Hopefully someday there will be universal standards among all truck/car/SUV builders as to what each vehicle can SAFELY tow. In my opinion, I believe most SUV's and light trucks are way overrated and I believe that the 5500 is still underrated.

 

[AH64ID]

Dodge used the new SAE standard to get the Max Tow ratings.

 

[Wertles]

So do these standards say that the 3500 pickup and the 4500 and 5500 C&C all will max out towing the same weight or am I misreading the information?

 

[HBarlow]

I read the allpar article with a grain of salt before I posted it. The owner/editor of allpar is not a truck guy so doesn't always understand the details when he includes truck reporting.

All I read in the article that is new is the new MaxTow option which will be for Ram 4500/5500s only and requires 4. 88 gears to get a 30,000 lb. GCWR. I haven't consulted the tables to see what rpms would be required at 65-70 mph with a 4. 88 gearset but my gut instinct is I don't think I would want to go there.

Seems like a bit of overengineering to me but I'm no engineer and don't know how Ram approaches their ratings.

 

[NIsaacs]

Doesn't even mention the 3500 Diesel, just the gasser and it went up 3,000 lbs gcw to 20,000.



Nick

 

[Bill Stockard]

All I read in the article that is new is the new MaxTow option which will be for Ram 4500/5500s only and requires 4. 88 gears to get a 30,000 lb. GCWR. I haven't consulted the tables to see what rpms would be required at 65-70 mph with a 4. 88 gearset but my gut instinct is I don't think I would want to go there.



Seems like a bit of overengineering to me but I'm no engineer and don't know how Ram approaches their ratings.

I haven't run the numbers; however, with a 4. 88 ratio axle and 19. 5" wheels/tires on the C&C 4500/5500, I imagine the final drive ratios will probably be similar to a 4. 10 ratio on the C&C 3500 with 17" wheels/tires.



Bill

 

[CUMMINZ]

I would not run 4. 88 gears in no way. Maybe with 22" tires.

 

[NIsaacs]

I would think the 19. 5" low profile overall diameter tire would be very close to a 17" regular tire.



Nick

 

[HBarlow]

Bill is right. The 4. 88 gears don't make that large a difference with 19. 5" wheels and the Aisin six speed automatic.

I pulled up Ken Lenger's magic spreadsheet and plugged in 4. 88 gears and 19. 5" wheels/tires and 70 mph is still pretty close to 2100 rpm.

I had always assumed 4. 88 was a big jump but it is not.

A new Ram 4500 with the MaxTow option including 4. 88 gears would probably make a very nice combo for a heavy fiver.

 

[AH64ID]

With stock tires the C&C with 4. 88's will be at 2460 rpms at 75, 2300 at 70, 2130 at 65, and 1970 at 60. . not bad for a 4500/5500.



With stock tires the 3500 Max Tow will be at 2125 at 75, 1980 at 70, 1840 at 65, and 1700 at 60.



The final drive of the C&C is 3. 07 and the 3500 Max Tow is 2. 58, so the C&C is quite a bit lower, but again that's it's market. The tires are only 2. 7% taller in terms of rev/mile.

 

[JWey]

Hi AH,

Just curious if you happen to know what the rpm's would be with the 444 gears which I think come in the 4500 c & c? I currently have an 08 5500 with 488 gears and the stock 19. 5's. It is a manual trans and at 60 mph I am at 6100 rpm's. I'm considering buying a new 4500 with the automatic and was hoping the taller rear would help drop the revs some so I could have a more comfortable highway rev and save some fuel as well. Thanks.

 

[AH64ID]

The OD of the G56 is much shorter than auto.



With the auto you would have the following rpms with 4. 44's and the auto.



75: 2240

70: 2090

65: 1940

60: 1790

 

[RVTRKN]

What about the speed limiter for the 4500-5500, won't that effect the ability of your max RPM/MPH regardless of the tire size?

 

[HBarlow]

Hi AH,
Just curious if you happen to know what the rpm's would be with the 444 gears which I think come in the 4500 c & c? I currently have an 08 5500 with 488 gears and the stock 19. 5's. It is a manual trans and at 60 mph I am at 6100 rpm's. I'm considering buying a new 4500 with the automatic and was hoping the taller rear would help drop the revs some so I could have a more comfortable highway rev and save some fuel as well. Thanks.

You can calculate your own answers using this spreadsheet:

<TABLE style="WIDTH: 343pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=455><COLGROUP><COL style="WIDTH: 49pt; mso-width-source: userset; mso-width-alt: 2377" span=7 width=65><TBODY><TR style="HEIGHT: 12. 75pt" height=17><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: transparent; WIDTH: 343pt; HEIGHT: 12. 75pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl66 height=17 width=455 colSpan=7>http://www.klenger.net/dodge/general-reference/gear-speed-calculator. xls</TD></TR></TBODY></TABLE>

Open the speadsheet, select the transmission of your choice, and plug in your own differential ratios, tire sizes for your application.

<TABLE style="WIDTH: 343pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=455><COLGROUP><COL style="WIDTH: 49pt; mso-width-source: userset; mso-width-alt: 2377" span=7 width=65><TBODY><TR style="HEIGHT: 12. 75pt" height=17><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: transparent; WIDTH: 343pt; HEIGHT: 12. 75pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl66 height=17 width=455 colSpan=7>Ken Lenger, the author, was once a TDR member and Dodge-Cummins owners. He has a website with lots of interesting information and aids such as the gear ratio vs. speed calulator.
</TD></TR></TBODY></TABLE>

 

[HBarlow]

Hi AH,
Just curious if you happen to know what the rpm's would be with the 444 gears which I think come in the 4500 c & c? I currently have an 08 5500 with 488 gears and the stock 19. 5's. It is a manual trans and at 60 mph I am at 6100 rpm's. I'm considering buying a new 4500 with the automatic and was hoping the taller rear would help drop the revs some so I could have a more comfortable highway rev and save some fuel as well. Thanks.

You can calculate your own answers using this spreadsheet:

<TABLE style="WIDTH: 343pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=455><COLGROUP><COL style="WIDTH: 49pt; mso-width-source: userset; mso-width-alt: 2377" span=7 width=65><TBODY><TR style="HEIGHT: 12. 75pt" height=17><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: transparent; WIDTH: 343pt; HEIGHT: 12. 75pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl66 height=17 width=455 colSpan=7>http://www.klenger.net/dodge/general-reference/gear-speed-calculator. xls</TD></TR></TBODY></TABLE>

Open the speadsheet, select the transmission of your choice, and plug in your own differential ratios, tire sizes for your application.

<TABLE style="WIDTH: 343pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=455><COLGROUP><COL style="WIDTH: 49pt; mso-width-source: userset; mso-width-alt: 2377" span=7 width=65><TBODY><TR style="HEIGHT: 12. 75pt" height=17><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: transparent; WIDTH: 343pt; HEIGHT: 12. 75pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl66 height=17 width=455 colSpan=7>Ken Lenger, the author, was once a TDR member and Dodge-Cummins owners. He has a website with lots of interesting information and aids such as the gear ratio vs. speed calculator.

Your problem is the G-56 manual six speed. The Aisin will give you two overdrive ratios with sixth gear being a 0. 63 to 1 overdrive ratio.

I now see that the 4. 88 ratio would be a good choice for heavy towing if you have the Aisin six speed. Not so good if your truck has a G-56 manual.



</TD></TR></TBODY></TABLE>

 

[AH64ID]

You can calculate your own answers using this spreadsheet:



<TABLE style="WIDTH: 343pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=455><COLGROUP><COL style="WIDTH: 49pt; mso-width-source: userset; mso-width-alt: 2377" span=7 width=65><TBODY><TR style="HEIGHT: 12. 75pt" height=17><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: transparent; WIDTH: 343pt; HEIGHT: 12. 75pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl66 height=17 width=455 colSpan=7>http://www.klenger.net/dodge/general-reference/gear-speed-calculator. xls</TD></TR></TBODY></TABLE>



Open the speadsheet, select the transmission of your choice, and plug in your own differential ratios, tire sizes for your application.



<TABLE style="WIDTH: 343pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=455><COLGROUP><COL style="WIDTH: 49pt; mso-width-source: userset; mso-width-alt: 2377" span=7 width=65><TBODY><TR style="HEIGHT: 12. 75pt" height=17><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: transparent; WIDTH: 343pt; HEIGHT: 12. 75pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl66 height=17 width=455 colSpan=7>Ken Lenger, the author, was once a TDR member and Dodge-Cummins owners. He has a website with lots of interesting information and aids such as the gear ratio vs. speed calulator.

</TD></TR></TBODY></TABLE>

Be sure to use rev/mile with that spreadsheet and not just input the tire size. For 265/70/17 the difference is 3%, and with 225/70/19. 5 the difference isn't as bad at 1. 2%. Howevere since most tire mfgr's now publish rev/mile its a more accurate calculation.

 

[JWey]

Thanks HB and AH, I appreciate the feedback!