JK Wrangler 3.8l vs 3.6l Pentastar

M

MtnBubba

Observer
I have a 2009 JKU Rubicon that is in near pristine stock condition. (22,000 miles) I'm wanting to do some mods and upgrades, (AEV Bumpers, suspension, rack) basically aimed at overlanding without limiting its usefulness as a daily driver in WY.

So, It's has held it's value well and I was wondering, is it worth spending money on a 6 yr old JK, when I can possibly trade it in or sell it myself and get a discounted 2015 for not a terrible upgrade cost. Obviously there are the warranty differences. (lifetime powertrain on the 2009 and reset of the number to bumper for 3 years on a 2015) Other items that come to mind that I know about are the slightly nicer interior, and the 3.6l Pentastar vs the 3.8l in my 2009. As a stock JKU the 3.8l gets horrible mileage. I know I shouldn't worry about mileage on a jeep or when considering a build, but is the 3.6l any better? Are there any improvements to the brakes or electronic traction control computers since 2009? Anything I'm missing and is there anything where the 2009 is better than what is made now to point me toward using it for my build?

I hope this isn't specifically answered somewhere else. I did some searching and didn't find what I was looking for.
 
Last edited:
T

toymaster

Explorer
I have a 2008 JK and am well versed in the Jeep world. The new 3.6 and new auto transmission puts the 3.8 to shame for that reason and that reason alone I say upgrade to a 2015. There have been zero other improvements. Nothing is better on the 2009 besides it is paid off and the lifetime warranty.

Do you still have the lifetime warranty on the 2009? Is that the 'warranty' you are referring to? This is a major factor.

From what you are saying you have a JKU with an auto transmission. Truly the worst combination for power and fuel mileage for the underpowered 3.8. I have a JK and manual so the 200 hp is livable especially running lower gears. Also, not a DD with ~30K since January 2009. I have thought about upgrading but for me it is not worth it.
 
D

damon.l

New member
the 3.6 puts the 3.8 to shame????

ya, on the top end it def does. the low end? go look at dynocharts. they are pretty much on par.


im in the same exact spot. im currently on a 3.8 (2008 JKUR on 37s on a 2.5 lift) looking to go to a brand new JKUR with the 3.6 on nothing more than 35s. a new 3.6 with a magnison blower would be fantastic, but upgrading from an older 3.8 to a new 3.6, you could even possibly look at keeping the old jeep and just installing a V8. the 5.3 options from motec (lswrangler.com) was always what i drooled over.
 
M

MtnBubba

Observer
Yes, it is a 3.8l attached to an automatic. It's not a daily driver... yet. My daily drive is a 2002 Tahoe with the 5.3l Vortec. I love that truck and motor.

I just looked it up and didn't realize that I had a lifetime powertrain warranty. I guess there is more value to that than I had considered. I was referring to the reset of the bumper to bumper warranty with a 2015. I know there are probably some items that might get excluded if I start changing out parts, but a lot of stuff would still be covered.

I just being cautious I guess about doubling down on the 3.8l engine. The 2009 also has the hard plastic interior. I know it's not a huge improvement with the newer softer panels, maybe that's a negative with UV damage and cracking of the softer materials over time?
 
Last edited:
T

toymaster

Explorer
^^^^^^^^^ Bad news. You have to have your jeep inspected at a dealer every 5 years. You have like 30 days on either side of you buy date to get the inspection done.

If the inspection is not done you lose the warranty. I was 3 weeks to late and they canceled mine. I assume if you did not know about it you did not get it done and now it has been 6 years.
 
M

MtnBubba

Observer
toymaster said:
^^^^^^^^^ Bad news. You have to have your jeep inspected at a dealer every 5 years. You have like 30 days on either side of you buy date to get the inspection done.

If the inspection is not done you lose the warranty. I was 3 weeks to late and they canceled mine. I assume if you did not know about it you did not get it done and now it has been 6 years.
Click to expand...

Yeah, I didn't get it inspected. Easy come, easy go.
 
O

Omar Brannstrom

Adventurer
gallery_2_46_206669.jpg


med_gallery_2_46_253610.jpg
 
Cedo Nulli

Cedo Nulli

Observer
What about just installing a blower on your 3.8L? RIPP and Magnuson both make good superchargers that have some great reliability. RIPP is more high-end RPM HP/Torque and runs higher boost (8-12 psi), where the Maggie is more even off idle (6 psi). Both require 91+ octane and run about $5-8K and install easy. You'll get nearer to the power of the V8s for much lesser cost, but there is never a replacement for displacement; it's just a more cost-effective option based on your use.
 
K

kojackJKU

Autism Family Travellers!
I would vote, just drive it. Why spend extra money and have another payment. My 2011 hauls me, the family, all our gear and then some, at highway speeds all day, gets 12.5l/100km on average with 33's and 2" of lift. I have driven the pentajesus and its not that big a difference. Def. not enough for me to justify trading in my paid off jeep for another car payment.
 
You must log in or register to reply here.

Forum statistics

Threads
186,850
Messages
2,888,731
Members
227,377
Latest member
blkcad

Members online

Total: 790 (members: 43, guests: 747)
Top