Ok experts, I need your expertise. I got rid of my 2006 Dodge Ram 1500 5.7 and bought a 2000 Ex V10 which I love. It has a K&N intake, 80k miles although this is debateable because it came with 315's (bf goodrich all terrains) and I doubt the speedo has been recalibrated and I belive it has the stock 3:73 gears.

I am basing my situation on information received on my GPS so I hope it helps.

I took my trailer out this weekend it weighs 5400 lbs fully loaded. I was really looking forward to towing it for the first time with the Ex and was suprised (not in a good way) with the response. According to my gps I was going about 65 mph and was hitting about 2600 rpm As I started a climb a hill it was about 3000 RPM and losing speed the steeper the clime it would jump to 4000 rpm and that was trying to keep the rig at 50 mph. I was tense listening to the engine roar. On the flats and around town with the trailer was great you wouldn't know it was back there but highway speeds and hills was not what I expected. I didnt have this problem with the Dodge so I was a little dissapointed.

I am sure my gearing has something to do with the problem but would like to get some input. Or maybe this is normal and I am just not used to it.

What do you folks thing?

 

Your HP peak is 4250. I wouldn't worry a bit about running right there all day long.

Your tires are killing the towing performance. You should either have a set of wheels with 265's for towing (plentiful & cheap on eBay) or regear to at least 4.56.

I imagine your Dodge wasn't running a 3.50 rear end, right? That's pretty much what yours is with those tires. But lighter weight, higher HP, better effective ratio all made your Dodge "feel" better.

 

Assuming you have a V10 as I am not familiar with the ratios needed with Diesel. I have a V10.

I had 3.73 with 315 (35") tires on it. The spedo is off 8-9% meaning a stated 60 is closer to 65. That is a great set-up for empty traveling, but not good for towing and in town driving. When I pulled a 6000 pound trailer with my 3.73 and 35s...i decided on gears. I now have 35s and 4.56. This is much better for towing and for in town driving, but not so good for unloaded traveling as the rpms are much higher than I would like and higher than seems efficient. I have no MPG data for the unloaded highway traveling as I have not taken it out like that....however, in town mileage has increased slightly which is to be expected. If you tow alot, I recommend you re-gear it. If you plan to stay with 35s and only 6000 lbs of trailer, 4.30 would do great. Heavier towing and 4.56 would be better. I only went to 4.56 due to planned 37s when these wear out, putting me better than 3.73s and 35s were.

4.30 gears with 35s is closest to stock 3.73
4.56 gears with 35s is closest to stock 4.10
4.88 gears with 35s is closest to stock 4.30

Many will say 4.30 is ideal effective gear ratio with a V10, but it is a big jump when you are happy with the 3.73s as I was. Depends on towing. 3.73 was never a desirable gear ratio for heavy towing.


You must figure out for sure what gears you have before you decide to upgrade them. Lift the back and turn the rear tire as you count the drive shaft rotations...with your setup. you should see the driveshaft rotate 3.4 times with one full tire rotation. 3.73 with 35s gives you roughly an effective 3.4 gear ratio.

 

I had pretty much the same feeling even with 4.56 gears. I pulled a friend's 23' Carolina skiff across the state, around the hills of ocala, I either had to turn off the cruise control or lock out OD to keep a decent speed. I think I did better fuel mileage wise with the OD off.

If I were to do it again and had a trailer to pull, I would have put 4.88 in. The mod motors don't seem to care about gear ratios mileage wise. So for the extra @$$ pulling, you wouldn't loose much by going a step deeper than 4.56.

 

I won't argue with Monsta very often, but that's lots o' spin. What's the relationship between HP peak and the advisability of using it for hours on end?

The V10 likes to rev, compared to diesels & big block V8s, but I think that's going to far. Better check your oil level daily and upgrade to an 88 gal gas tank
(The 88 is hyperbole.)

Now we agree

 

The mod motors can and will run just fine at high RPMS all day long and never care!

That is for sure. I'm not sure why the gas Ex's came with 3.73's as an option ever. It's just plain to low...

 

So, I guess my best bet is regearing and 4.30 or 4.56 are my options. I will do that, anyone know what it would cost (ballpark) to regear? Also what can I expect to happen during daily or highway driving without towing when I do regear.

 

With the 315's I wouldn't bother with 4.30. 4.56 is as high as I would go, and if I could do it again I would do 4.88. It's not just the height, but the extra width and rolling resistance.

It's around $1,000 per axle, so figure $2k for a 4x4.

It will get out of it's own way with the new gears. I noticed a minimal loss in mileage, but it could get off the line much quicker.

 

If you do it yourself you can save a ton of money, but you need to know what to do!

Otherwise like above, it is a win-win!

 

Fuel usage issues non withstanding, the V10 will run up to its limiter of around 5200-5400 RPM. Certainly running it at 4250 will increase fuel consumption and accelerate engine wear over the long haul but it won't hurt the engine at all. My point was mainly to express that running it anywhere up to it's computer limited peak will not harm the engine. ...course I didn't say that but...

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Honestly I think your best bet (read: less $$) would be to buy a complete set of take-offs from eBay or similar for about $500-600 and use them when you tow. But that's just me .

 

Honestly I think your best bet (read: less $$) would be to buy a complete set of take-offs from eBay or similar for about $500-600 and use them when you tow. But that's just me .[/quote]




The problem is I have a six inch fabtech lift and it would just look funky.

 

Local powertrain shop here charged me $750 per axle to regear my 2000 Durango. $1,000 is pretty steep.

 

Yes... That would very funky indeed! Looks a re- gear is in order. A number of us have (me included) and I think everyone of us believe it's the best performance mod for the V10.

 

So, my last questions is 4.30 or 4.56? and will my RPM's drop while I tow?

 

4.56

Your RPMs will "drop" simply because you'll not downshift as much.