Engine: Upgrade 3.8 to 3.6?

[Dzine07]

I currently have a 2011 JKU Mojave Edition (Sport with 3.73 gears).

When i purchased my Jeep i did so just before the 3.6 hit the showrooms. As you might expect I ended up getting a great deal on one of the remaining 2011 3.8 liter Jeeps. I never looked back.

Fast forward to today and here's my dilema.. I've been planning to build my expo Jeep with 35's and 3.73 gears. I was hoping to start this winter and begin ordering the parts to then officially starting my build. Unfortunately i'm having second thoughts because i'm worried the JK with the 3.8 and 3.73 will not be an ideal foundation to build my expo rig on. I really do like my Jeep in its current form. The unknown for me is what the Jeep will be like AFTER I add the lift, some tires, some racks in the back for gear and possibly a small expo trailer.

I'm curious if anyone on here has driven both engines and more specifically, if anyone has a 3.8 with larger tires. I would like to get some feedback from you guys before I take that next step.

Thanks for reading!

 

[jomobco]

Trade it in. It would be easier. Or blow it.

 

[2025 deleted member]

Gear it to match the 35's. Something lower than 3.73 for sure.

 

[Yosh_Lopez]

I am running 3.73 and 35's on my 08 Wrangler (6 speed MT). Getting around town, it does fine. However, hills require aggressive downshifting in order to maintain speed. After this last roadtrip, a re-gear has moved to the top of my mod list.

For daily driving duties, it gets the job done.

 

[Cole]

Hated my 3.8l JKUR with 35s and 5.13s. Gutless! Sucked Fuel!

 

[Dzine07]

I am running 3.73 and 35's on my 08 Wrangler (6 speed MT). Getting around town, it does fine. However, hills require aggressive downshifting in order to maintain speed. After this last roadtrip, a re-gear has moved to the top of my mod list.

For daily driving duties, it gets the job done.

I have an auto, wondering if that's better or worse..?

Thanks for the feedback. Around town I could stomach the anemic 3.8 but traveling out west to Moab in April i'm not sure what to expect with my current set up.

Do you think think the upgrade to a 3.6 is worth ditching the 3.8?

 

[Dzine07]

Trade it in. It would be easier. Or blow it.

That was my first thought! ..but after pricing out the newer wranglers and with their current 9 week backlog for 2015 i don't foresee any incentives. I may have to dip into my build fund to make the change and push out the 35's and lift for another year.

 

[Cole]

I have an auto, wondering if that's better or worse..?

It's much worse! The auto behind the 3.8L is only a 4 speed. (welcome to 1977) Part of the reason the auto 3.6l is faster is that it gained a gear (5 speed....welcome to 1995:coffeedrink:......he'll the new Cherokee has a 9 speed!!)

The 4 speed at also didn't have a great choice of gear ratios.

 

[Dzine07]

It's much worse! The auto behind the 3.8L is only a 4 speed. (welcome to 1977) Part of the reason the auto 3.6l is faster is that it gained a gear (5 speed....welcome to 1995:coffeedrink:......he'll the new Cherokee has a 9 speed!!)

The 4 speed at also didn't have a great choice of gear ratios.

Geezus.

 

[Dzine07]

It's much worse! The auto behind the 3.8L is only a 4 speed. (welcome to 1977) Part of the reason the auto 3.6l is faster is that it gained a gear (5 speed....welcome to 1995:coffeedrink:......he'll the new Cherokee has a 9 speed!!)

The 4 speed at also didn't have a great choice of gear ratios.

That being said, is the 3.6 significantly better? I'm trying to justify the upgrade but if i'm in a foxhole either way the best option seems to be wait until 2017.

 

[TG Smith]

I have a 2014 3.6 JKU. It sits on 35 in. Duratracs w Hutchinson Wheels and a 2.5" AEV lift. Not gonna win any awards for speed or power but it does the job and I live in Colorado at about 7,000 feet. I took it out to Moab this spring and averaged 21 MPG with another adult and full gear. If you're talking engine swaps, you know the type of $$$$ plus headaches you're looking at. Have you looked at the AEV conversion to a Hemi? Also, you might check some of the smaller dealerships for inventory in smaller markets? Tough choice…

Alternatively, I installed a Rugged Ridge Modular Snorkel (don't run the snorkel around town) with a high-flow air filter and I think it has given me some more MPG. It was a PITA to install and I've reinstalled it twice as it rubs on the shock tower at 2,500 RPM which you can hear in the cabin. You might consider a snorkel to get cooler, better airflow?

Good luck!

 

[toxicity_27]

I've driven both a 2011 auto with 3.73 and a 2013 auto with 3.73 both with 35s. The 2013 was hands down better. I also own a 2013 with 3.73 and 35s however I have a manual. I know quite a few people who are content with their 3.8 however they did gears. Even with mine I plan on going to 4.56. I would suggest looking into gears before trading. See if there are any around Duluth (there should be) that people will let you drive.

 

[GFA]

See the thread I started about improving fuel mileage in a JKU....

Either trade up or wait it out till the next model because if your unhappy already a re gear and 35's will leave wishing you had waited. I'm running 33's and 5.13's and it's still a dog, never mind the huge hit in MPG's I took because of the re gear.

 

[Dzine07]

I have a 2014 3.6 JKU. It sits on 35 in. Duratracs w Hutchinson Wheels and a 2.5" AEV lift. Not gonna win any awards for speed or power but it does the job and I live in Colorado at about 7,000 feet. I took it out to Moab this spring and averaged 21 MPG with another adult and full gear. If you're talking engine swaps, you know the type of $$$$ plus headaches you're looking at. Have you looked at the AEV conversion to a Hemi? Also, you might check some of the smaller dealerships for inventory in smaller markets? Tough choice…

Alternatively, I installed a Rugged Ridge Modular Snorkel (don't run the snorkel around town) with a high-flow air filter and I think it has given me some more MPG. It was a PITA to install and I've reinstalled it twice as it rubs on the shock tower at 2,500 RPM which you can hear in the cabin. You might consider a snorkel to get cooler, better airflow?

Good luck!

Not talking engine swaps, just getting a new JKU altogether. Good tip on the snorkel thanks for the feedback.

What gears are you running with 35's?

 

[Dzine07]

I've driven both a 2011 auto with 3.73 and a 2013 auto with 3.73 both with 35s. The 2013 was hands down better. I also own a 2013 with 3.73 and 35s however I have a manual. I know quite a few people who are content with their 3.8 however they did gears. Even with mine I plan on going to 4.56. I would suggest looking into gears before trading. See if there are any around Duluth (there should be) that people will let you drive.

Thanks for the feedback, was the 2013 you drove a huge leap in terms of drivability with 35's? By chance did you get it on the highway? I would be content with my 3.8 if I didn't have this lingering doubt that there's something better out there (i.e. 3.6).