4.0L vs. 3.7L

Matt and Jeff, WOW! Didn't mean to cause such a comotion (did I spell that right?) Anyway, I am not an engine aficianado (did I spell that one right, too?) BUT love the Wrangler and my luck with the I-6... I want both... so I guess I will be considering a 05 or 06 Rubicon come next spring. In your opinions, is the Rubicon overkill for someone who isn't going to crawl it over boulders?

Thanks for your responses... it's awesome to see such passion! But can't we all just get along???? Later guys!

By the way, thanks for setting me straight about the exact engine that is going in the truck...

Matt Macchiarolo wrote:

Quite possibly, but if you aren't going to get a Rubicon, do get a TJ with the Dana 44 rear end, and avoid the 3.07 ratio

[snip]

How 'bout a Wankel in your Wrangler?

...

"Commotion". "Aficionado".

The Rubicon would be overkill for most situations, but you might get stuck someday, and the logos are always good for posing.

Earle

Numerically lower gear ratios can be bad for highway and off road use both. A 3.07 with the 4.0l can get you out of the power band at highway speeds, especially if you spend too much time in 5th or 4th gear in some settings. It can even get you out of the economy band, which is about 80% of the power band. What people call "lugging" just wastes fuel and causes excessive engine wear. Despite what many people think, fuel economy does not automatically go up, as engine speed goes down.

Off road, it can leave you with no gear low enough for the tight spots.

Earle

The 3.07 ratio with stock ~29 inch tyres means that you are doing about 2000 revs at 75 mph in 5th Consequently, you are always having to change down to go up even moderate hills on the motorway, and which rather takes the edge of cruise control. If you go to 31s, you are doing ~ 2200 rpm at ~70 in 4th which works a lot better - however this means you go down steep hills offroad a bit faster than you would like. Better off with the 3.73 ratio or the 4.10 with 31s as the Rubicon has.

Dave Milne, Scotland '91 Grand Wagoneer, '99 TJ

You found out wrong - the '07 Wranglers are equipped with a 3.8L V-6

here's a link:

This is a longitudinal version of the Mini-van pushrod 2 valve / cylinder V-6.

Despite my love and respect for the 4.0 in-line motor I think this one is a proven design with a good track record... more than a few million have been delivered in Mini-vans. My wife's last two Mini-vans were so equipped and they are torquey (even off-idle) smooth running engines.

In addition to the business reasons given in various replies a strong reason for the V-6 is its shorter length giving room for better crash performance without increasing wheelbase (without intruding into the passenger compartment because of it's length).

reboot

Noneyabusiness proclaimed:

Much rather have a high torque engine such as a turbine or steam. Unless you gear the typical gasoline Wankel to about 6:1, the torque can best be described as wishful thinking. Or you could poke around for the

1100 Hp Ingersoll Rand Wankel or see if any of the two-stage diesel Wankel tank engines are available--presuming they wouldn't turn your drive shafts into wound up rubber bands.

I LOVE the fact that they have this engine! Altho I'll miss that traditional Jeep I-6 4.0 chugg it used to make, (I owned 4 of them) I still have my 4.2 CJ-7 to keep me comforted while driving around town.

If I had all the cash in the world, I'd yank the 3.7 and drop that 4.7 in it in a minute! Think of all that low end power torque and all those horses. You'd probly be able to break that coveted 103 mph! (At least that's all my

2000 Sport could muster)

You really should be using low range on trails. :-)