Legendary 4.0 L I6 VS 3.8L V6

[Miro]

Found an interesting comparision between the new JK and the old TJ

Which one to go for???

Power: 6-speed manual transmission. Automatic isn’t even an option to consider. It might be a bit hard to get used to the position of the 6th gear as it’s scarily close to reverse.

Options: I definitely want a set of metal half doors, probably in addition to the standard full doors. Still confused about various tops and how they work or don’t work with the different door options.

Now the really big question is: the 2006 TJ or the 2007 JK?

The 2006 TJ Rubicon comes standard with an AMC 190HP, 4.0L, Power Tech inline-six, considered one of the best off-road engines ever made. Also standard are 31-inch tall LT245/75R16 tires on 16-inch aluminum wheels. Music should sound pretty good coming from a 7-speaker system that includes a full center console-mounted subwoofer, 2 midrange speakers in the instrument panel, and 2 full-range speakers mounted in the overhead speaker pods. Cool!

On the other hand, the 2007 JK Rubicon has a standard Chrysler 3.8L, 12-valve, 205HP, V6 engine. Seventeen-inch aluminum wheels sporting LT225/75R17 mud terrain tires are also standard. The six-speaker stereo system has an MP3 input audio jack, ideal for my iPod. Rock rails are standard, unlike on the 2006. This next-generation Jeep is 5.5 inches longer and 1.4 inches taller than the existing model, with a 2.1-inch-longer wheelbase and 2.4-inch-wider track, but with a tenth of an inch less ground clearance. Despite it being taller, there’s a fraction less headroom in front and back in the JK, although shoulder room has increased in both areas. Where the 2007 exceeds over the 2006 is storage behind the back seats: over 17 cubic feet vs slightly less than 12 cubic feet on the 2006 TJ. Not sure I care for the single-hinge windshield vs two hinges. Both model years have dual Dana 44 axles, a heavy-duty transfer case with an ultra-low 4:1 ratio, and 4-wheel disc brakes. The optional security package for the 2006 comes standard on the 2007. Turning diameter is the same. Everything else is little details.

The Jeep forums are abuzz about which engine to covet. The die-hards are asking “why fix what works?” and the modernists are answering “better gas mileage, more power, newer technology!” The 4.0L of the TJ was introduced in 1987 with a Renault engine control system. In 1991, when Chrysler acquired the brand, the control computer was redesigned and the intake ports were raised. Chrysler also enlarged the throttle body and redesigned the intake and exhaust manifolds for more efficiency, and the fuel injectors were replaced with higher flowing units. Small changes were made to the cylinder head and engine block every couple of years until 1998, after which it has remained mostly the same. The 3.8L of the new JK was introduced in 1991 into Chrysler’s Fifth Avenue, Imperial, and minivans (yuck!) and it, too, has had some changes; the intake was redesigned in 1994 and the compression ratio was increased in 1998. The real claim to fame of the 3.8L is the addition of a variable intake system in 2001, increasing horsepower and foot-pounds of torque, but according to the forums the jury is still out as to whether it will have a negative effect on low, rock-climbing RPMs.

The “new” 3.8L engine just doesn’t seem so new to get all that worked up about since its genesis was only a few years after the 4.0L.

[surfer]

Maaaaaaaaaaaaaan, change the font color, my eyes are blured

[Chuck]

Power: 6-speed manual transmission. Automatic isn’t even an option to consider. It might be a bit hard to get used to the position of the 6th gear as it’s scarily close to reverse.

Options: I definitely want a set of metal half doors, probably in addition to the standard full doors. Still confused about various tops and how they work or don’t work with the different door options.

Now the really big question is: the 2006 TJ or the 2007 JK?

The 2006 TJ Rubicon comes standard with an AMC 190HP, 4.0L, Power Tech inline-six, considered one of the best off-road engines ever made. Also standard are 31-inch tall LT245/75R16 tires on 16-inch aluminum wheels. Music should sound pretty good coming from a 7-speaker system that includes a full center console-mounted subwoofer, 2 midrange speakers in the instrument panel, and 2 full-range speakers mounted in the overhead speaker pods. Cool!

On the other hand, the 2007 JK Rubicon has a standard Chrysler 3.8L, 12-valve, 205HP, V6 engine. Seventeen-inch aluminum wheels sporting LT225/75R17 mud terrain tires are also standard. The six-speaker stereo system has an MP3 input audio jack, ideal for my iPod. Rock rails are standard, unlike on the 2006. This next-generation Jeep is 5.5 inches longer and 1.4 inches taller than the existing model, with a 2.1-inch-longer wheelbase and 2.4-inch-wider track, but with a tenth of an inch less ground clearance. Despite it being taller, there’s a fraction less headroom in front and back in the JK, although shoulder room has increased in both areas. Where the 2007 exceeds over the 2006 is storage behind the back seats: over 17 cubic feet vs slightly less than 12 cubic feet on the 2006 TJ. Not sure I care for the single-hinge windshield vs two hinges. Both model years have dual Dana 44 axles, a heavy-duty transfer case with an ultra-low 4:1 ratio, and 4-wheel disc brakes. The optional security package for the 2006 comes standard on the 2007. Turning diameter is the same. Everything else is little details.

The Jeep forums are abuzz about which engine to covet. The die-hards are asking “why fix what works?” and the modernists are answering “better gas mileage, more power, newer technology!” The 4.0L of the TJ was introduced in 1987 with a Renault engine control system. In 1991, when Chrysler acquired the brand, the control computer was redesigned and the intake ports were raised. Chrysler also enlarged the throttle body and redesigned the intake and exhaust manifolds for more efficiency, and the fuel injectors were replaced with higher flowing units. Small changes were made to the cylinder head and engine block every couple of years until 1998, after which it has remained mostly the same. The 3.8L of the new JK was introduced in 1991 into Chrysler’s Fifth Avenue, Imperial, and minivans (yuck!) and it, too, has had some changes; the intake was redesigned in 1994 and the compression ratio was increased in 1998. The real claim to fame of the 3.8L is the addition of a variable intake system in 2001, increasing horsepower and foot-pounds of torque, but according to the forums the jury is still out as to whether it will have a negative effect on low, rock-climbing RPMs.

The “new” 3.8L engine just doesn’t seem so new to get all that worked up about since its genesis was only a few years after the 4.0L.

Is this better ?

[adiga]

can we have it in white color pls

[iguana]

can we have it in white color pls

Sorry Chuck, I edited it. Is it OK now Adiga?

[Miro]

Sorry guys for the color, Now YOUR OPINIONS PLEASEEEEEEEE

[Doc]

My opinion is buy a land rover the engine has been now been in use for 35 years and they still cant make it reliable,

go for the 4.0 TJ, it's solid and reliable, why fix it if its not broken, as with most things newer engines are actualy less reliable than the old ones, too many electrics to hep fuel economy and emissions etc. your still hard pushed to beat the old american V8's for reliability and drivability.

in with the old and out with the new is what i say.

[Chuck]

The 3.8 seems to be not a that much younger construction than the 4.0 L.

Maybe the fuel efficiency and such things of the 3.8 L is better than the 4.0L but if it will be a engine for the future, i do not know.

I mean this people at Jeep made a dicision for the 3.8 L, so i think they have an idea why they do so.

[Doc]

Chuck, all new car designs and engine decisions are based on profit and loss + efficiency, the days of making a decision based on what’s best for the car and drivers are long gone, car and engine design now is heavily governed by government pressure for low emissions / fuel economy and accountants. It would be nice to think that the guys at Jeep know best and I’m sure they do, but what they decide is best and what accountants decide is best is normally two different things.

The truth hurts but it is the truth.

[Bulldozer]

I ll GO for I6 4.0L engine

[Chuck]

I ll GO for I6 4.0L engine

I ll go for I6 4,6L engine

[iguana]

I ll GO for I6 4.0L engine

I ll go for I6 4,6L engine

I was waiting to hear this from you Chuck

[Miro]

Yes Iguana, me too, the I6 rules

[Chuck]

I ll GO for I6 4.0L engine

I ll go for I6 4,6L engine

I was waiting to hear this from you Chuck

You know me,

your answer should be

I ll go for I6 4,7L engine

[iguana]

I still didn't start my project yet. Wait, maybe I will have a 5.0 or a 5.7L. Just looking at the options, the cost, the modifications required and how to pass muroor