Ram 6.4L Hemi vs good ol' 8.1L

[BurbMan]

Had the flu this week so spent a lot of time sitting around watching TV and Googling stuff....I got to thinking that my next truck will probably be a well-equipped Ram 2500, crew cab, 6'4" bed, with the 6.4L Hemi.

The real question is the drivetrain....I thought briefly about the manual transmission, but the traffic around here has gotten so bad I'm afraid I don't have the patience to shift anymore. After losing 2 automatics while towing, it seems to make sense though....

I don't tow far enough or heavy enough to need a diesel, TT loaded is not quite 9k lbs. I'm thinking the 6.4 with the 4.10 rear would make a nice combo.

So obviously the Big Question is, how will it tow compared to the 8.1/4.10 combo I have now? How is the 68RFE transmission, is it durable?

I'm also not seeing ram boxes or an IBC option, are these not available on the power wagon?

The other big question is how recent model years stack up....ideally I'd like to get 14-16 truck that somebody else had paid the depreciation on.

Would appreciate any pointers from guys who know the Ram truck line...

[ib516]

Frostbitte wrote:

wilber1 wrote:
I really don't understand why Ram offers the 8 spd with the 5.7 1500 and not with the 6.4 2500. They come in models that can easily handle the 6.4's torque. In fact it is the automatic option on the Hellcat which produces 650 lbft.

Rumour has it that the 8-speed for the 6.4 2500 is in the works. Don't have any specifics or dates though...

I realize it's a different application, but if they can makes the 8 speed able to hold 800hp in the demon, they should be able to make it survive towing duty.

[Frostbitte]

wilber1 wrote:
I really don't understand why Ram offers the 8 spd with the 5.7 1500 and not with the 6.4 2500. They come in models that can easily handle the 6.4's torque. In fact it is the automatic option on the Hellcat which produces 650 lbft.

Rumour has it that the 8-speed for the 6.4 2500 is in the works. Don't have any specifics or dates though...

[BurbMan]

LOL I hear ya! I was joking about the Lone Star because I'm a NYer, not a Texan. I have been looking at the Laramie, though. Proxim, your TT sounds almost exactly like mine weight wise. The 1-2 shift gap doesn't really concern me too much, since I've only got a 4-speed trans now.

In fact the 4L80E ratios in the Burb are 2.48, 1.48, 1.00, 0.75, and in the 66RFE are 3.23, 1.84, 1.41, 1.00, 0.816, 0.625.

So what you guys are saying is a big 1-2 gear jump is actually better than what I have now. I've always felt I needed another gear between 2 and 3, and this does it. The 66RFE doesn't hit 1.00 until 4th, where I hit it in 3rd now, plus I have 2 OD gears instead of 1 so that's what helps the empty mileage a lot.

IB, I forgot you had posted extensively about this truck when you got yours, and I remember now ow impressed you were with its towing abilities.

Thanks for posting this:

ib516 wrote:
8.1L is 340hp @ 4200 RPM / 455tq at 3200 RPM.
6.4L is 410hp @ 5600 RPM / 429tq at 4000 RPM.

I just looked at the GM offerings, and the 6.0 is 360hp/380tq, reminding me of why I didn't buy it back in 2001. The DMax diesel puts out the real power, but it's an $11,000 premium!!! Sorry, but that doesn't make sense for me for the number of times I tow the TT....at this point in my life the truck is 5x more likely to be spotted at Home Depot or with an equipment trailer behind it than at a CG....

[Community Alumni]

I have a '18 6.4L DRW. The current TT is 8,500 - 9k and I get about 8.5 mpg while towing. I'm averaging 13.5 mpg in the city and 16.5 on the highway. MPGs could be better if I had less "fun" in it lol. I've towed up a few 12% grades and it scooted up them just fine with no drama. The 1st to 2nd gear gap is noticeable, but not something that bothers me.

When it came to trims we debated between the SLT and the Lone Star levels for a while. The SLT gives you a good amount of features standard and the Lone Star give you just a little bit more. She sat in a Laramie and instantly fell in love with it. I enjoy my current sleeping arrangements so guess what we got:B

[Camper_G]

BurbMan wrote:
Had the flu this week so spent a lot of time sitting around watching TV and Googling stuff....I got to thinking that my next truck will probably be a well-equipped Ram 2500, crew cab, 6'4" bed, with the 6.4L Hemi.

The real question is the drivetrain....I thought briefly about the manual transmission, but the traffic around here has gotten so bad I'm afraid I don't have the patience to shift anymore. After losing 2 automatics while towing, it seems to make sense though....

I don't tow far enough or heavy enough to need a diesel, TT loaded is not quite 9k lbs. I'm thinking the 6.4 with the 4.10 rear would make a nice combo.

So obviously the Big Question is, how will it tow compared to the 8.1/4.10 combo I have now? How is the 68RFE transmission, is it durable?

I'm also not seeing ram boxes or an IBC option, are these not available on the power wagon?

The other big question is how recent model years stack up....ideally I'd like to get 14-16 truck that somebody else had paid the depreciation on.

Would appreciate any pointers from guys who know the Ram truck line...

BM,

I'm towing 6k with my 17/6.4/3.73 combo and I'm very happy with it. Plenty of power in the mountains and the chassis is solid. I'd look to get as new/low mileage truck as you can. Look new, if you buy at the right time of year you can get great incentives that you could probably get brand-new for the money you'll spend on a 2yr old truck. They hold their value so well.

I don't mind the transmission. It's world's better than the 6 speed my 2015 Silverado had. I don't miss that Chevy at all with this ram and I have a tradesman. Good luck. All 3 of the big 3 build great trucks. It's all personal preference. I like Ford and Ram the best, but that's just me.

[VernDiesel]

Wilber I swear if I found a 6.4 truck with a bad transmission I would try to see if the 8 speed could be made to work. You would get measurably better mileage & towing out of it. Like not 1 or 2 percent but 10 & possibly up to close to 20 percent in some scenarios. Didn’t the 5.7 in the 1500 get over 10 percent better economy. Plus it became a much more proficient tower from the better gear spacing even when useing taller 3.21 & 3.55 gears for better highway economy. You gain on both fronts. I could live with wheel chalks & avoiding parking on a hill when towing heavy.

Ib516, Cool. 440 HP 4,700ish & 490 TQ 3,500ish ie not requiring anywhere near Hemi rpms from upgraded rebuilt tow tune. Not to knock the Hemi it’s well built with quality forged internals. I like the old reliable 6.0 also but it’s just weak. Ford’s V 10 was another good reliable tower as was the old Cadillac 472/500 with a 4l80. Sorry was reminiscing.

http://www.raylarengineering.com/vortec-8100-496cid-truck-performance-parts.html

Hmnn can’t get link to work type this. Www.raylarengineering.com

[ib516]

Just for comparison purposes...

8.1L is 340hp @ 4200 RPM / 455tq at 3200 RPM. (Was the 8.1L in the Burb rated the same as the pickups?)
6.4L is 410hp @ 5600 RPM / 429tq at 4000 RPM.

[ib516]

blofgren wrote:

campingken wrote:
Send a PM to ib516. He owned a 6.4 with 4.10 gears that he was very happy with. Before he bought this truck he did a post on why he chose the 6.4 over a diesel (his previous truck was a 5.9 Cummins).

x2. He has several good Youtube videos on it as well.

Here I am!

Yes, I enjoyed my Ram 6.4L Hemi/4.10 combo. I pulled a 12k 5er with it, ran at 21k GCW. It did fine. There was only one time I tried accelerating pulling a grade and couldn't with my foot flat on the floor. You can't be afraid of high RPMs when pulling though. Mine ran in 4th or 5th, never 6th. Mpg was about the same in 4th or 5th while pulling, 7-9 mpg, usually 8 mpg hauling the 5er. It was a 37' unit with 3 slides. (Cougar in sig). For reference, the previous 5.9L Cummins/Megacab/3.73/3500 SRW got about 10 or 11 mpg hauling the same 5er, so about 2 mpg better. It also did 2-3 mpg better when running empty, and used much lower RPM while towing.

The truck would do over 60 mph in 2nd gear, so if you lost speed on a grade (to 45-50 mph before downshifting), it would downshift to 2nd gear and get up to 5500 RPM or so before shifting to 3rd. The 1-2 gap folks have mentioned only comes into play when accelerating from a stop, and it's only noticeable when loaded. The engine RPM drop just a bit too much from 1st to 2nd, and it takes about a second to recover and climb back into the power band where the engine RPMs start climbing again. It is noticeable, but not a deal killer.

Empty, in perfect conditions, it would do 18-20 mpg, but was usually around 15-16 mpg at 65 mph. I was pretty impressed with the mpg actually considering it had 4.10s and it is a big truck.

Performance was excellent, towing or not. Really happy there. I pulled up and over every grade I could find in the Canadian Rockies with mine.

I would buy another 6.4/4.10 truck in a heartbeat if I needed a 2500 truck. I have a small hybrid now, and will likely not get anything much bigger, so a 1500 will do me when I can afford to upgrade.

[wilber1]

VernDiesel wrote:
This has been covered a few times here. Ram hasn’t done the 8 speed in an HD because the parking paw is not rated strong enough to hold a truck & trailer to rated capacity on a hill. .

Thanks, good to know. Hopefully they can resolve it, the 8HP is one hell of a transmission and actually has fewer parts than the 6 speed.

I also think anyone who relies on a parking pawl to hold the truck and trailers rated capacity on a hill is just asking for trouble.

[autorot8]

I didn't read all the posts but will input my impressions/experiences. Mine has the 3.73, my trailer loaded is around 8500 - 9k. I live at 4000. Towed from California into Oregon, and never had a problem. When I did that, trailer was fully loaded with household items and truck bed was also fully loaded with household items (furniture, books, etc.). When I approached the mountain grades, I locked it into 3rd and was able to maintain 60 mph at around 3200 rpm. In my opinion it did as good as my old PS 6.0. I was quite pleased. Over the passes I averaged around 8 mpg.

[kzspree320]

When I came back from my first long tow with my Ram 2500 with Hemi and 4.10 last year, I started a thread to inform others how it went. I copied and pasted it below. May be more detail than you want, but here you go.

I just got back from almost a 2,000 mile trip, which was the first long tow for my 2016 Ram 2500 gasser. I thought some on the gas vs diesel fence might be interested in how well this gasser tows my almost 35' Columbus fiver (tall profile, 13"4" high) which loaded to camp weighs around 12,000-12,500 lbs.

Trip was from Louisiana through MS, Tennessee and Kentucky and then back through Alabama. Almost all of it was Interstate and I towed at 65 mph. For your info, last truck was a 2015 Ram 2500 with the 6.7 Cummins, which was destroyed in the August 2016 Louisiana flood. I have towed the same fifth wheel with both so I can compare.

Let me start by saying it does not tow like the diesel. Yes, it has to shift more because it has less torque. If you want the easiest towing, and the extra $7-8K upfront and potential costlier repairs once the warranty is up doesn't concern you, then just get the diesel. Please diesel owners don't hijack this thread, I'm just trying to give info so people can make decisions. If you tow regularly in the western mountains at high altitudes, just get the diesel.

If most of your towing is in the eastern US and not at high altitudes, this gasser tows pretty **** good. Yes, it tows at 1,000-1,200 rpms high than the diesel, but that's what it was designed to do. With tow/haul on, it never towed in 6th. Towing in 5th (still an OD gear) was about 2,300 rpms and 4th was about 2,800 rpms. On the longer and steeper pulls, it occasionally used 3rd at about 3,500 rpms. It could hold 65+ mph anywhere we went if you want. For the entire trip, I estimate it probably spent about 55% of the time in 5th gear, 40% in 4th gear, and 5% in 3rd gear. Almost all of the 3rd gear was in Tennessee and Kentucky. I will take this to Colorado in the future, but I do know I will have to bring my patience at times on the long pulls through the passes (yes, I love Colorado).

I hand calculated my towing mileage, so here it goes by tank - 8.1, 8.1, 7.6, 8.0, 8.5, 7.8, 7.2, 7.8, 8.1, 8.0, 8.1. Since I like to have close to half a tank, most fillips were between 150 and 180 miles. In the diesel, I would have probably averaged 10.5-11.2 mpg and filled up about every 200-250 miles. The 7.2 mpg tank was against a stiff headwind. Looks to me like the overall average was about 8 mpg. That's about what I thought when I bought the truck. Non towing I get about 13 around town and 16 on the highway.

My truck is rated to pull almost 16K. I don't think that would be fun. But at under 13K or so, it does a good job overall and great for a gasser. I do not regret my decision on this truck. YMMV depending on how you use the truck.

I read a lot of ib516's posts before buying the truck. Overall, I agree with his towing impressions. Hope this helps others in the truck buying process.

[GordonThree]

What's wrong with the long horn trim?

I'm not partial to the exhaust tips protruding through the bumper

[Me_Again]

BurbMan wrote:
Pretty sure I'm not getting the Lone Star LOL....

Did you mean Long Horn or the market specific Texas "Lone Star" feature twin of the Big Horn?

[BurbMan]

Spent some time this morning looking at the numbers, and the Power Wagon has a max GVWR of 8510, which is a non-starter considering the burb has 8600 now. Oh well, that winch in the front is cool!

Looking at the tow ratings (they are SAE J-whatever compliant) it looks like I pick up about 2000 lbs capacity all around. Ram's GVWR is 10000 vs 8600 for the burb, and for the 2500 crew cab short bed, the curb weight is 6700, identical to the burb. So that means Ram's payload would go up from burb's 1900 to 3300 lbs.

Max trailer weight is 15620 vs 12000 for the burb and Ram's GCWR is 22800 vs 19000 for the burb.

So if you subtract GVWR from GCWR, the effective max trailer weight for the Ram is 12800 and for the burb 10600.

Now to try and navigate the absurd number of trim levels, between SLT, laramie, Big Horn, etc. Pretty sure I'm not getting the Lone Star LOL....

[LIKE2BUILD]

Power Wagon is not a good choice for GVWR, it’s really a sport truck. Definitely go with a ‘14 or newer 2500. The coil spring suspension rides very nice and is plenty firm when needed. I have a crew cab SLT. The interior is pretty good, not absolute top of the line but I’m happy with it. The crew cab is extremely spacious. There is plenty of leg room front and back regardless of seat position.

KJ