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Old 07-19-2011, 02:23 PM   #1
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I4 vs I6

Hey so I was starting wonder about which engine i should get in my jeep. I've been told by a few people to get an I6 if i wanna go mudding and wheeling.
So my question is...
1. Will I notice much of a difference (in abilities) between the two engines when I'm off roading, be it mud or rock?
2. I get the general idea of less cylinders = less gas, but will there really be a noticeable difference?

Thanks guys!

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Old 07-19-2011, 02:23 PM   #2
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Old 07-19-2011, 02:27 PM   #3
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If you want to offroad it at all you will be much happier with the 4.0 than the 2.5.
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Old 07-19-2011, 02:30 PM   #4
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I heard that there's no big difference offroad between the two engines. But if you want to go with 35+ tires id imagine a I6 being better

But onroad a I6 is sooooo much better
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Old 07-19-2011, 02:32 PM   #5
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1. Yes, especially with bigger tires. You can make up the difference with gears to a point, but only to a point.
2. No, maybe a couple of miles per gallon at best. Fewer cylinders mean less fuel, but less power. That means you're on the gas more to do the same thing.

I passed up plenty of I4 Jeeps looking for mine. Unless it's for commuting or something, it's just not worth it.
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Old 07-19-2011, 02:34 PM   #6
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Dont forget that the I4 isnt as reliable and tends to blow up over twice as much as an I6
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Old 07-19-2011, 02:56 PM   #7
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Quote:
Originally Posted by BigD91 View Post
Hey so I was starting wonder about which engine i should get in my jeep. I've been told by a few people to get an I6 if i wanna go mudding and wheeling.
So my question is...
1. Will I notice much of a difference (in abilities) between the two engines when I'm off roading, be it mud or rock?
2. I get the general idea of less cylinders = less gas, but will there really be a noticeable difference?

Thanks guys!
whoever told you the bigger difference is off road had it backwards. the 2.5 can hold its own off road. driving at highway speeds is where you will notice the difference.

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Dont forget that the I4 isnt as reliable and tends to blow up over twice as much as an I6
true although i think the 2.5 is still a lot better than a 2.4
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Old 07-19-2011, 04:07 PM   #8
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Quote:
Originally Posted by flyfishnevada View Post
1. Yes, especially with bigger tires. You can make up the difference with gears to a point, but only to a point.
2. No, maybe a couple of miles per gallon at best. Fewer cylinders mean less fuel, but less power. That means you're on the gas more to do the same thing.

I passed up plenty of I4 Jeeps looking for mine. Unless it's for commuting or something, it's just not worth it.
Those are both valid points.

I actually think the 2.5L falls flat on it's face on the pavement. It has NO get up and go. You have to drive it so aggressively, which gets very tiring for you...and the motor. Also, AX5 behind a lot of 2.5L is terribly unreliable.

I got rid of my 2.5L, and I'll never look back. I'm much happier in my 4.0L, and wish I bought the 4.0L the first time around.
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Old 07-19-2011, 04:25 PM   #9
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I actually think the 2.5L falls flat on it's face on the pavement. It has NO get up and go. You have to drive it so aggressively, which gets very tiring for you...and the motor. Also, AX5 behind a lot of 2.5L is terribly unreliable.
It's like a double whammy. You take a less reliable engine (and tranny) and push it harder. That's not a good combo. Plus, it's not like the 4.0 is exactly tearing it up on the highway. I can only imagine how sluggish the 4 is.

I agree, off road it's probably fine, but even then you're going to have to push it harder to move the big tires than you would the 4.0. If you have one, you make due, but I doubt there's too many folks out there who aren't wishing they had the six, especially when the supposed advantage, gas mileage, never really make an appearance.
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Old 07-19-2011, 07:57 PM   #10
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Quote:
Originally Posted by BigD91
Hey so I was starting wonder about which engine i should get in my jeep. I've been told by a few people to get an I6 if i wanna go mudding and wheeling.
So my question is...
1. Will I notice much of a difference (in abilities) between the two engines when I'm off roading, be it mud or rock?
2. I get the general idea of less cylinders = less gas, but will there really be a noticeable difference?

Thanks guys!
I've owned/own TJs with both the 2.5 and 4.0 and while the 4.0 is the more desired choice, my 2.5s never let me down, neither did the AX5. They will do everything a 4.0 would do off-road, and more in some cases... Mud, rocks, hill climbs... No problem, but that is not based on the engine alone, mad skills at the wheel can get you through anything lol! Gas mileage is about the same from my experience, my 2.5 would get better depending on how its driven, it also ran cooler on the trails but would heat up a burrito just fine on the manifold. Hills and stop and go traffic can make a mpg difference with bigger tires
I drove my 98 4cyl with 33x9.50s/ 32x11.50s on the interstate all the time and had no problems keeping up. I love the 4.0 but I wouldn't hesitate to buy another 2.5. Both are easy to work on and relatively inexpensive to replace if need be.
The above was merely my experience with both of the dinosaur inlines that we will sorely miss but keep alive.
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Old 07-20-2011, 02:18 AM   #11
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Well thanks for all the input guys! definitely leaning heavy toward the 4.0 now

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Dont forget that the I4 isnt as reliable and tends to blow up over twice as much as an I6
THANK YOU! haha definitely wouldn't want that to happen on my first car, let alone my first jeep
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Old 07-22-2011, 07:10 PM   #12
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I4s ranks right up there with hemroids and tooth decay!
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Old 07-22-2011, 07:31 PM   #13
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simple answer

when it comes to a jeep more is better, I6 is more motor therefore better
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Old 07-22-2011, 11:15 PM   #14
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Quote:
Originally Posted by old_blue
simple answer

when it comes to a jeep more is better, I6 is more motor therefore better
Sorry but I have to disagree, sometimes less is more... More motor isn't always the answer. Sure it's nice to have more power on the road but really, a 4cyl can be just as good as the 6 if its driven properly and geared appropriately. Off-road the I4 is great, it has the grunt to make any obstacle and lacks the torque to snap axles if you can drive it properly. Just think back over 7 decades to the flat head 134... It had like 70 HP?? The history books don't have any complaints...
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Old 07-23-2011, 08:54 AM   #15
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I disagree, the 4's are notorious for blowing rods out of the side. And back 7 decades ago, no one was lifting their 4 cylinder and putting 33-35 inch tires on them and reving the engine to the moon to get it to move.
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Old 07-24-2011, 02:08 AM   #16
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I honestly hate these threads. I have a 2.4, running 33s on 3.73 gears, and i have no issue keeping up in traffic even at 70 mph, even going up hills. After a while you learn to cope with how and when to shift between 6, 5, and 4th. Hell im usually in the fast lane passing.

Plus i got 22 mpg driving to and from work a week, granted i did nothing but work driving. Thats all the input i have.

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