2.5 versus 2.4

Chris

Chris

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Is the 2.4 engine found in the 03-06 SE models any more powerful than the 2.5 engine found in the 97-2002 SE models?

I'm not talking about on paper either, I'm curious if anyone has driven them both in stock form and noticed if one was noticeably any better than the other?

@Rob5589 and @StG58 got me thinking about this.
 
I would say a drag race but, that damn 6 spd grinds bad if I shift too fast, would probably blow a synchro :crazylick: :D

Honestly, it does fine for my needs. No 33's, no trailers, not a daily commuter. It would probably be still acceptable with 33's and proper gearing for my use.
 
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Rob5589 said:
I would say a drag race but, that damn 6 spd grinds bad if I shift too fast, would probably blow a synchro :crazylick: :D

Honestly, it does fine for my needs. No 33's, no trailers, not a daily commuter. It would probably be still acceptable with 33's and proper gearing for my use.
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The thought of drag racing SE TJ's cracks me up. That would be a lot of Sturm und Drang to not much result. Probably entertaining but not very productive.

I could see 33's on an SE, but you would absolutely have to regear it to 5.13's to even start to live with it. I don't know about the 2.4, 17 more HP not with standing, but one of the issues with the 2.5 is that you have to carry more RPM's to get anything at all done. There just isn't enough there to idle through and over stuff. There are lots of times where I have to snatch low range to get the combination of RPM and ground speed to wend my way through steep, tight spots. I don't need four wheel drive for traction, but I need low range for pulling my sorry ass up and over.

I could see pulling a light trailer, along the lines of a 14' aluminum Drift Boat or a small off road trailer. That would work out nicely. I pulled 14' aluminum boat with fishing gear all the time in my 4 banger XJ. Worked out just fine. That was with 235/75R15 tires though. Ya just have to know your limitations. I don't think any of the 4 bangers like to haul any sort of weight. Big tires exacerbate those problems rapidly.

I daily drive my 2.5. It goes anywhere and everywhere that I point it. It rarely complains about it. When you're not cruising, keep the RPM's around 3,000, and it's happy as a clam. It does the speed limit on the Freeway just fine. It zooms the back roads just fine, and really loves third gear in the gravel. It also does fine just putting around town at 2,000 RPM, just downshift before you try to zoom off.

The 2.5 does great, you just have to use the gear shift lever instead of the skinny pedal.
 
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Does the 2.4 actually have any more horsepower than the 2.5?

I wonder why they went from the 2.5 to the 2.4, are there a lot of similarities with those two engines?
 
StG58 said:
Don't know about the 2.4, never drove one. The 2.5 is a good motor though, and the SE's are good Jeeps. Only once have I wanted more, and I just downshifted to third and hammered it out. Problem solved.
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Had a 2.5 in an '84 XJ once upon a time. 175,000 miles on it and it was plenty strong enough.
 
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Chris said:
Does the 2.4 actually have any more horsepower than the 2.5?

I wonder why they went from the 2.5 to the 2.4, are there a lot of similarities with those two engines?
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Theoretically, the 2.4 does have more HP at 147 HP and 135 ft/lbs torque than the 2.5 at 121 HP and 139 ft/lbs torque. I'm sure there are times that you would notice it, but probably not in the grand scheme of things. Those figures are close, but maybe not exact to a particular engine.

It's a lot like how they went from the 4.0 to the 3.8. The 2.5 is a pretty primitive engine in the grand scheme of four bangers. The 2.4 and the 2.5 are nothing alike other than the basics. They both seem to work though.
JP98 said:
Had a 2.5 in an '84 XJ once upon a time. 175,000 miles on it and it was plenty strong enough.
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Mine was an 87 XJ, and you're right. It was perfectly adequate for what I did with it. Young married guy with two kids. We did a lot of back country exploring in that thing, and all four of us actually slept in the back, with the back seat down and the front seats folded against the dash.
 
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I'm constantly amazed how much torque the AMC 2.5 puts out at low rpms. The 4.0 guys might laugh but when you compare it to other engines in this size and configuration, it does the job. I have to wonder if the 2.4 OHC engine is more like the Toyota 22R-E OHC 2.4's. My old 88 Xtra cab was the absolute shits in the bush. If you tried to grunt it anywhere near idle, it would instantly die. The Toyota was heavier than the TJ and it would bog in 5th at the slightest hint of gentle hill. The Jeep can hold 90kmh (55mph) in 4th up 8% with 2 people on 29" rubber.

Edit: I just tackled the same hill with 3 people. Still held the 90kmh/55mph.
 
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Mine is on 31's and has no issue chugging along trails all day long. In 4lo it can idle up some fairly steep grades. At times I do find I need some extra gear, 4lo is too much, 4hi not quite enough.
 
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Same here. 31's and stock gears. The only thing I wish I had right now is 4.88's and lockers. Sometimes I need more gear in 2wd but don't need 4x. A lot of times the ground conditions are perfect, but the little Jeep just won't pull enough in 2wd to idle uphill through the tight spots.
 
Chris said:
Is the 2.4 engine found in the 03-06 SE models any more powerful than the 2.5 engine found in the 97-2002 SE models?

I'm not talking about on paper either, I'm curious if anyone has driven them both in stock form and noticed if one was noticeably any better than the other?

@Rob5589 and @StG58 got me thinking about this.
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I've driven both and to me there is a world of difference. Both were stock, soft top, 5 speeds. The 2.4 had around 160k on it, the 2.5 had around 190k (supposedly rebuilt). The 2.4 is way superior in my opinion but I think it's because it handles rpm better than the old pushrod setup AMC designed.
This is just my experience, it's very unofficial.
 
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327YJ said:
I've driven both and to me there is a world of difference. Both were stock, soft top, 5 speeds. The 2.4 had around 160k on it, the 2.5 had around 190k (supposedly rebuilt). The 2.4 is way superior in my opinion but I think it's because it handles rpm better than the old pushrod setup AMC designed.
This is just my experience, it's very unofficial.
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It may be an old thread but I agree with you 100% I had a 97 with the 2.5 and an 04 with the 2.4, there's a considerable difference, the 2.4 accelerated better than the 2.5 and held highway speeds better. If I were ever in the market to buy another se model it would be one with the 2.4 in it.
 
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327YJ said:
I've driven both and to me there is a world of difference. Both were stock, soft top, 5 speeds. The 2.4 had around 160k on it, the 2.5 had around 190k (supposedly rebuilt). The 2.4 is way superior in my opinion but I think it's because it handles rpm better than the old pushrod setup AMC designed.
This is just my experience, it's very unofficial.
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This doesn't surprise me. Rarely does an auto manufacturer replace an engine unless it's better than the one it's replacing.
 
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I've driven both extensively also. The 2.5 has a little more low end, but the 2.4 kills it on the top end. The 2.4 is made to rev to 7k, but it's limited to 6k in the Jeep. The 2.4 is also much lighter aluminum block with aluminum heads, the 2.5 is all iron. I picked up 11hp after uncorking the exhaust and intake on my 2.4 giving it 121hp at the wheels at 4950. Still not enough power to turn 31s on the highway comfortably even with 4.10s and a six speed, but it has enough gears to go through pretty much anything offroad if your not afraid of the rev limiter. I'd really be interested to see what a set of different cams and a tune would do for it.
 
Chris said:
Is the 2.4 engine found in the 03-06 SE models any more powerful than the 2.5 engine found in the 97-2002 SE models?

I'm not talking about on paper either, I'm curious if anyone has driven them both in stock form and noticed if one was noticeably any better than the other?

@Rob5589 and @StG58 got me thinking about this.
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Chris. as you know I have the 2.5 in my Jeep but my wife has the 2.4 in her Compass and it's a dog. she would take my 2.5 any day. I have done extensive work on both engines and the 2.4 is a plastic fantastic POS.
 
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TJ4Jim said:
Chris. as you know I have the 2.5 in my Jeep but my wife has the 2.4 in her Compass and it's a dog. she would take my 2.5 any day. I have done extensive work on both engines and the 2.4 is a plastic fantastic POS.
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Really? I have no experience with anything other than the 2.5, and that was in a Cherokee XJ.

So I guess your experience is the opposite of the others above. I wonder if it has anything to do with the Compass potentially being geared differently, weight, etc.
 
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