Never thought of this!

[Desert_Rat]

I had someone ask me at work today why Jeep put the 4.0l I6 instead of a beefier V8........and why is it that Jeep is the only one that uses the I6?......Unfortunately I had no answer for him.....Someone give me a clue!

[Bounty__Hunter]

Probably a liability thing, v8's are just too much power for a short wheelbase for the general public.

There are a lot of other I6's out there. The Ford 300 straight 6 is an awesome engine, tons of torque. The 4.2L I6 in our '03 Chevy Trailblazer puts out 275 HP stock

[K-Phat]

The I6 is just such a great all around engine. I just love mine. Plus if one wants to but a V-8 in a Jeep it can be done. In addition to the trucks Bounty mentioned with I6 BMW uses them in some of their cars too.

[firemanharry]

V8 = too much power (like there IS such a thing)
More torque to the I6 compared to the V6

[Snitty]

i think it is mostly due to the success in using the I6 for so long.... much like the solid axle... its working so well... keep it... the 4.0 is an amazing motor... great power for stock, great torque for stock... so easy to work on.. and if maintained, they run forever

[Sully]

Jeep kept the I6 because it performs very well,and doesnt suck as much gas as a V8.Plain and simple.

[exjay33]

Jeep at one time did put 304s in the cjs just got away from them when gas prices went through the roof besides the 6 makes it power down low where you need it for wheeling. There are rumors that it is coming to an end though (3.7 v6) we shall see.

[Inspector-Gadget]

Hello Desert_Rat,

Here is another theory:

“The Energy Policy and Conservation Act of 1975 required passenger car and light truck manufacturers to meet Corporate Average Fuel Economy (CAFÉ) standards. The CAFE standards are applied on a fleet-wide basis for each manufacturer; i.e., the fuel economy ratings for a manufacturer's entire line of passenger cars must average at least 27.5 mpg for the manufacturer to comply with the standard. If a manufacturer does not meet the standard, it is liable for a civil penalty of $5.00 for each 0.1 mpg its fleet falls below the standard, multiplied by the number of vehicles it produces. For example, if a manufacturer produces 2 million cars in a particular model year, and its CAFE falls 0.5 mpg below the standard, it would be liable for a civil penalty of $50 million.] For light trucks (including vans and sport utility vehicles) the 1993 CAFE standard was 20.3 mpg.”

It wasn’t until the CAFÉ standard became law that American auto manufacturers got serious about fuel economy, and that is also when the large displacement, slow turning V-8 disappeared faster than a banana at a monkey convention.

Just a thought...

Gadget

[graewulf]

Originally Posted by firemanharry

V8 = too much power (like there IS such a thing)
More torque to the I6 compared to the V6

ok, i gotta ask.. where'd you hear that????? a v-6 engine by its very nature has higher torque...

[far_right]

a v-6 engine by its very nature has higher torque...

but no as torquey at low rpm as I engines, that is why huge diesels are in an I config and not a V

[jeepin916]

Originally Posted by K-Phat

The I6 is just such a great all around engine. I just love mine. Plus if one wants to but a V-8 in a Jeep it can be done. In addition to the trucks Bounty mentioned with I6 BMW uses them in some of their cars too.

All of the bmw's use I6 engines except for the new v8's and 12's and the old 4 new bmw's use the 6 as a base engine and there powerfulll, believe me i work for beemer hehe

[Tug-n-pull]

Just tell em it is a Jeep thing! hehe Kinda like when your mom said cause I am the mom that is why! tug

[firemanharry]

firemanharry wrote:
V8 = too much power (like there IS such a thing)
More torque to the I6 compared to the V6


ok, i gotta ask.. where'd you hear that????? a v-6 engine by its very nature has higher torque...

I think Far Right has already replied to your question for me (my hat's off to you Far Right).

I'm not any kind of mechanical engineer or rocket scientist. In fact, I barely made it out of High School...........perhaps you could enlighten me as to the "very nature" of a V-6 so that I may refrain from ignorantly posting my humble opinions in the future. I thank you in advance for the knowledge that we are about to receive.

[Snitty]

anything with an I configuration will have better torque than the same built motor with a V configuration... the force applied to the crank by the connecting rods will be applied on a single vertical plane rather than two diaginal planes... and the force applied in the differing directions can often cause a lack of consistancy in the rotational force (torque)

[Bounty__Hunter]

I had always thought, given a V6 and I6 with the same displacement, that the I6 would have more torque. Not much scientific fact to back it up, just what I had been led to believe over the years.

[firemanharry]

That's what I was always led to believe Bounty.

[jeepin916]

Originally Posted by Snitty

anything with an I configuration will have better torque than the same built motor with a V configuration... the force applied to the crank by the connecting rods will be applied on a single vertical plane rather than two diaginal planes... and the force applied in the differing directions can often cause a lack of consistancy in the rotational force (torque)

wow what book did u get that from snitty? hehehe i know iv red that somewhere, and i know from all the schools i went to and all the engine building classes i took allways said that in line engines make more torque than v engines for the simple reason that there is more force from the piston comming down and up in an Inline engine than there is from a V engine, and that force is caused by rod angle, which is much more than a v engine thereby causing more torque. which makes sence but i dont know if i explained myself correctly

[Snitty]

we are basically saying the same thing.... i was getting into a little more specific explaination of the angles... but the idea expressed is the same

[Utah_jeepster]

actually its weight to torque ratio.
The lighter short wheel based Jeeps dont need such a massive engine to move it on and off road.
The "I" configuration produces massive amounts of torque at lower RPM's compared to a "V" configuration.
For a "V" motor to produce the same amount of torque you need to lengthen the stroke but reduce the compression ratio to a 10-1. The Scout 345 as an example.
The "V" configuration was designed to produce lots of torque at higher RPM's, the only problem was weight and fuel comsuption. For a good example look at the muscle cars of the 60's and early 70's.
Alot of top end speed but very little low end toque unless the motor was modified and the chassi re-geared for the 1/4 mile strip racing.
With a jeep you dont need nor want high RPM torque. But straight low end grunting power.
The "I" configuration has been around longer than the "V" design.
With the ability to save on casting weight, less moving parts,bearing seats for the cam and crank and space saving of the "I" configuration has made the straight 4 and 6 motor a Jeep trade mark for the amount of torque they produce.
A proven motor design that has lasted for over 85 years( the first cars were an inline 4). And will last another 20-30 more till the 4 pack ( "V-4") hybird motors will dominate automotive industry

[joejeepny]

I thought the v engine was designed for more torque. The offset applies torque to the crank at different points in its rotation providing a smoother stronger stroke.