8th Gear on Highway

[Lil'Mike]

I have the 3.6L and 3.21 gears, and my truck will rarely shift into 8th when cruising on the highway at any speed above 75. If I can manage to get into 8th, it’ll downshift on any slight grade. Is this to be expected? Wind resistance/physics? It’s disappointing to not be able to take advantage of the extra gear for MPG reasons, which is why I picked the V6 in the first place!

FWIW - the steering wheel and gas pedal start to vibrate when in 8th, maybe indicating the truck is struggling...

RAMCares confirmed I have latest TCM/HCP/PCM updates.

 

[Dusty1948]

I have the 3.6L and 3.21 gears, and my truck will rarely shift into 8th when cruising on the highway at any speed above 75. If I can manage to get into 8th, it’ll downshift on any slight grade. Is this to be expected? Wind resistance/physics? It’s disappointing to not be able to take advantage of the extra gear for MPG reasons, which is why I picked the V6 in the first place!

FWIW - the steering wheel and gas pedal start to vibrate when in 8th, maybe indicating the truck is struggling...

RAMCares confirmed I have latest TCM/HCP/PCM updates.

In the past I have noted that V6 Ram 1500s came with the 3.55 axle as standard, with 3.21 and 3.92s optional. In any case, the V6 versions with the 3.55 would probably lend itself to using eighth gear with more opportunity.

That being said, in 7th gear you are already in an overdrive gear ratio that would closely approximate 8th gear with a 3.55 differential. If this is a relatively new vehicle you'll find that as the engine and transmission break-in the transmission will shift into 8th gear more often. I have a Hemi with the same axle ratio and I see basically the same thing as you. Over time, however, I've noticed it in 8th gear more than when the vehicle was new.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 038628 miles.

 

[Lil'Mike]

Thank you, Dusty. Yep, I have about 4000 miles now. Sounds like I need to not worry about it and let the engine and transmission continue to break in and loosen up?

 

[ethemartian]

Thank you, Dusty. Yep, I have about 4000 miles now. Sounds like I need to not worry about it and let the engine and transmission continue to break in and loosen up?

I had the 4th gen with the v6 I'm guessing 3.55 gears and would downshift all the time going any over pass in the highway in flat South Florida. Got the hemi now and can stay in 8th gear most of the time with the 3.21 gears

 

[User_3336]

3.21 Axle ratio in a V6, that's part of the issue........ Is this a CREW cab as well?????

 

[User_3336]

Its the most annoying thing in the world. V6 and a 3.21, especially in the quad or crew. CONTINUALLY 6-7-8.

Take a HEMI in the 3.21 in a CREW, for example, maybe slight downshifting. 7-8, mostly stays in 8 unless a hill.

Hemi/3.92/CREW. Cruises in 8th about 95% of the time.

I had the 4th gen with the v6 I'm guessing 3.55 gears and would downshift all the time going any over pass in the highway in flat South Florida. Got the hemi now and can stay in 8th gear most of the time with the 3.21 gears

 

[silver billet]

Its the most annoying thing in the world. V6 and a 3.21, especially in the quad or crew. CONTINUALLY 6-7-8.

Take a HEMI in the 3.21 in a CREW, for example, maybe slight downshifting. 7-8, mostly stays in 8 unless a hill.

Hemi/3.92/CREW. Cruises in 8th about 95% of the time.

And if you want to pretend you have a 3.92 but you have the 3.21, just lock out the top gear to 7 and you have the same final gear ratio as the 3.92 in 8; no more downshifting

I have the 3.21 hemi and it works great for my usage; it definitely downshifts on moderate slopes on the freeway, but I swear that 98% of the time my truck is turning the wheels, it spends that time in 8th.

 

[Lil'Mike]

Yeah, v6 with 3.21 - I didn’t realize it would be a problem as I’ve had HEMIs in all my previous Rams and my wife has the 3.6 in her AWD Durango and it gets great mileage, is pleasant to drive, and has been very reliable. I’m realizing maybe not so much in the Ram...

 

[User_3336]

I have the same V6 in my 2019 Jeep Grand Cherokee. The V6 is fine for a car or light SUV.

But it struggles, in my opinion, carrying a full size Quad/Crew Cab, especially when paired with a 3.21 gear ratio. 4x4 struggles even more.

Yeah, v6 with 3.21 - I didn’t realize it would be a problem as I’ve had HEMIs in all my previous Rams and my wife has the 3.6 in her AWD Durango and it gets great mileage, is pleasant to drive, and has been very reliable. I’m realizing maybe not so much in the Ram...

 

[njt07]

Not to go off on a tangent, but I wonder how the ED paired with a 3.92 would drive? MPG?

What MPG do you get with the V6 and 3.21? 3.55?

 

[Lil'Mike]

About 18-19 combined with the V6 3.21 so far... 4000 miles, just about.

 

[User_3336]

That's depressing, I'm averaging 19.2 with a Hemi with a 3.92.

About 18-19 combined with the V6 3.21 so far... 4000 miles, just about.

 

[Lil'Mike]

No kidding

 

[392DCGC]

Thank you, Dusty. Yep, I have about 4000 miles now. Sounds like I need to not worry about it and let the engine and transmission continue to break in and loosen up?

Break-in is not going to change anything. Reality is you have a full size pickup with a naturally aspirated V6 and 3.21 gearing that lacks in power at low RPM. You can't reasonably expect it to maintain 8th gear at 75 MPH. The 5.7 barely maintains 8th through any slight incline at those speeds. You are still benefiting from a V6 and 3.21 gears in terms of MPG in relation to your driving. It may not be a meaningful benefit, but it's there nonetheless. That said, a NA V6 in a full-size pickup exists for one reason... helping those CAFE requirements. I would never buy one, and I doubt you will again.

 

[Lil'Mike]

Thanks, guys. This is all very informative, I appreciate the replies. I should have spent some time on this forum before making the purchase! I’ll keep that in mind next time ‘round.

 

[millerbjm]

I had a 2014 1500 quad cab 6.4 box 4x4 with the 3.6 and 3.21 gears and I consistently saw over 20mpg in a 50/50 mix of city/highway. I often had passengers and always had a cap on and gear in the truck. I found that engine to be plenty powerful for normal use. I started out my search for a 2019 with the 3.6 in mind and only went with the 5.7 because the dealer had one on the lot with all my options that the financing had feel through on and he made me a good deal. I love the acceleration and power of the hemi but during the pandemic I've been driving in the city and getting heavier with my foot and even on summer gas my mileage is down around 15mpg. Long story short for a daily driver with occasional towing under 5,000lbs I think the 3.6 is a great $$ saver and a very reliable engine.

 

[User_3336]

definitely not questioning the 3.6 as a very reliable engine. Look how many other platforms its used in. What, how many Jeeps does this engine reside in? Remaining Chrysler vehicles, Chargers, Challengers, Journeys.....the list goes on.

But, as stated, it does struggle on a full size pickup, especially a Quad or a Crew, especially in a 3.21. you see next to none of these V6 trucks paired with a 3.92 axle ratio.

I looked at a local dealer's inventory, they've got a ton of classic crews WITH A V6.

I've seen some of the most beautiful trucks on the lot, clicked on the window sticker, and its a V6, and its been there a while.

Can you imagine putting a V6 in a REBEL? (surely there is no such configuration).

Guess what engines these trucks have? both Crew Cabs. Nice looking trucks!


Likewise an area dealer has a whole lot of 4.3 V6 Silverado's in a Crew (now, you talking about a dog). still sitting. And WTH was Chevy thinking putting a 4 cylinder turbo in a Crew Cab (I drove one, it sucks)

 

[Dusty1948]

In the case of Ram they probably are looking for CAFE credits, but these smaller engines would provide the same benefit for other manufacturers as well. The more recent trend around here by local towns and villages is to purchase their 1/2 - tons with V6s and maintain a very small number of 3/4 tons for the rare heavy work. Likewise tradespeople or small business owners generally don't care about power, whether they could really use it or not. As long as it gets the job done regardless how much throttle opening is required, a V6 is fine. They save on the initial purchase and lower their fuel costs. And if employees are using them they actually don't want to encourage power.

From my standpoint I can't see purchasing a 4x4 1500 Crew with a V6 even though the Pentastar is an exceptional, normally aspirated engine. But that's me. I suspect there is anything like a 4x4 1500 Crew Cab partly because of CAFE credits, but also because marketing believes that some new-to-truck lifestyle buyers will find the V6 more rational.

By the way, if you see a lot of a certain configuration vehicles on dealers lots it's likely due to a sales program. IE: in order to keep certain incentives, dealers must order a certain amount of a configuration before the model closes out.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 038716 miles.

 

[User_3336]

Dealers sometimes are shipped allocations in configurations they don't even want.
For example, when is the last time you seen an "HFE" model on the lot. In my brother's search, we seen one at a dealer's lot in the vicinity of where he bought his last week. No rebates/No inventives/measley dealer discount. They're screwed. this truck will sit on the lot forever. and guess what, it had a V6. The only thing that I could see on this truck that might consider it "High efficiency" was that a tonneau cover was included from the factory. Other than that, it was just like any other V6 Quad Cab on the lot. "HFE" = marketing bulls**t!

 

[silver billet]

GregHBNA, agreed that the the 3.6 pentastar is a great engine. I'd put it near the top of "regular/workhorse" motors. And also agree it doesn't belong with the 3.21 in the Ram.

But GM's 4.3 and turbo i4 work much better. I too have driven them, and it's not really a competition between those and the 3.6. They're still not hemi's, but they make much torque, and in the case of the i4 they make it really low down. You can say "it sucks", but compared to what. The Hemi? Ok... Compared to any other base engine in a truck from Ford/Ram? Nope. The i4 is a replacement for the 4.3, not the 5.3, and viewed in that light it does an amazing job for all those people who buy trucks to be used as "big passenger cars". You're not going to tow a 30 foot TT, but they're base engines. The 5.3 and the 6.2 and the 3.0 diesel cover towing.

Let's face it; I love my Ram, but the GM twins have better power train options all around. We need something to match the 6.2 v8 and 3.5 ecoboost, there is nothing. The 3.0 diesel is a strong performer, with much less lag and more power it seems than the 3rd gen ED. And the base engines (4.3 + turbo i4) are stronger than the 3.6.

Anyway, I'm rambling, but I prefer to keep Ram's feet in the fire to push them into better powertrains, we can't do that by pretending it's all sunshine and roses in the Ram because that really is their weakspot. (and my hemi ticks and clacks too much, at times I'm embarassed to drive it)