What’s 6th gear for???

[RoadiJeff]

What’s 6th gear for???

It helps to make a smoother transition from 5th gear on the way to 8th gear. Oh, wait...you have a 6 speed manual - nevermind.

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[AlamedaJeep]

US 50 - The Loneliest Highway. This is the type of road where I’ll use 6th and I’m happy to have it.

On other highways if there is traffic and variations in speed I usually just stay in 4th. Not much traffic and cruising along I’ll use 5th.

 

[jadewolf]

If you think 6th gear is useless in a JL, try driving a JK with 3.21 gears.

A Rubicon with 4.10 gears and stock tires is a much better setup than the 3.45s or even 3.73s.

The Pentastar works best in the mid 2k range. Below 2,000 RPM is way too low to run effifcently.

This, exactly. My JK Sport with 3.21 gears was absolutely useless in 6th after I put 33s on. And 5th was barely useable, too. The JL Rubi manual, however, is a dream to drive! I'm loving mine!

But yes, 6th gear is a highway cruising gear for conserving fuel on long, flat stretches of highway.

And I wouldn't worry about safety above 70. The speed limit out in the desert here is 80 and the JL is steady as a rock at that speed. I've gotten it up to about 88 a couple times and it was very comfortable. (By contrast, my JK felt like the apocalypse was nigh over 70mph.)

 

[omnitonic]

Do you not want it to be below 2400 rpm on the highway? The reason for 6th is to use less fuel....

The issue is topping every hill at 55 mph. Sure, it will go, and if I'm not in a hurry, I'll run 6th gear, and just fall in with the 18-wheelers. Then a little voice in my head says, "Wait a minute! You weigh under 5,000 pounds! Why are you running with the 80,000-pound trucks?!" Because I am in 6th gear. Right. I shouldn't do that. I am in an official Not Truck™, therefore there is no sensible reason for me to be running 55 mph in a 65 zone.

I've looked at the "instant fuel economy" numbers, and running in 6th just makes everything worse most of the time. 6th gear is completely useless unless you are in Florida or Kansas.

 

[Zandcwhite]

US 50 - The Loneliest Highway. This is the type of road where I’ll use 6th and I’m happy to have it.

On other highways if there is traffic and variations in speed I usually just stay in 4th. Not much traffic and cruising along I’ll use 5th.

Don't let the guys in the auto threads hear about this, they think they need 5.13's on 35's so their Jeeps will hold 8th gear ALL the time.

 

[Ridgway Jeeper]

The issue is topping every hill at 55 mph. Sure, it will go, and if I'm not in a hurry, I'll run 6th gear, and just fall in with the 18-wheelers. Then a little voice in my head says, "Wait a minute! You weigh under 5,000 pounds! Why are you running with the 80,000-pound trucks?!" Because I am in 6th gear. Right. I shouldn't do that. I am in an official Not Truck™, therefore there is no sensible reason for me to be running 55 mph in a 65 zone.

I've looked at the "instant fuel economy" numbers, and running in 6th just makes everything worse most of the time. 6th gear is completely useless unless you are in Florida or Kansas.

It is your final gear ratio that is too tall. The 6 speed works great with the Rubicons 4.10 gearing. I am pretty familiar with steep grades living in the rocky mtns. At 70 I was dropping less than 5 mph climbing the steeper hills and still passing the big trucks. On our 65 mph highways sixth has been working great in Colorado....

If downshifting for the hills bother you, why did you buy the manual? Sort of comes with the territory.

 

[Ridgway Jeeper]

I understand the rationale, but in reality the MPG is better in 5th than 6th on the highway. I drove for some time in both gears, 6th is typically working harder, especially on a grade. If I'm going 55 or less, I use 4th. This engine hiccups around 2k, it doesn't want to run slower.

On our 60 mph limit roads during tourist season when people forget how to drive and speeds almost never get to the limit, I will find myself running in 5th quite often. On the open desert highways to the north where traffic runs 70-75 I use 6th, it doesn't struggle in the least and for sure is getting better mpg than if I ran it in 5th.

 

[Zandcwhite]

The issue is topping every hill at 55 mph. Sure, it will go, and if I'm not in a hurry, I'll run 6th gear, and just fall in with the 18-wheelers. Then a little voice in my head says, "Wait a minute! You weigh under 5,000 pounds! Why are you running with the 80,000-pound trucks?!" Because I am in 6th gear. Right. I shouldn't do that. I am in an official Not Truck™, therefore there is no sensible reason for me to be running 55 mph in a 65 zone.

I've looked at the "instant fuel economy" numbers, and running in 6th just makes everything worse most of the time. 6th gear is completely useless unless you are in Florida or Kansas.

Ummm....downshift? The same thing an automatic does automatically, you should be doing when driving a manual. Lugging up hill at low rpms is terrible for an engine. Need to accelerate quickly, downshift. Want to maintain speed down a steep grade, downshift. It's a manual transmission, not a showtime rotisserie. You don't just "set it and forget it".

 

[Micky]

i use 6th when at highway speeds on flatish terrain. otherwise, it is better on 5th if you have some climbs.

 

[omnitonic]

If downshifting for the hills bother you, why did you buy the manual? Sort of comes with the territory.

Ummm....downshift? The same thing an automatic does automatically, you should be doing when driving a manual.

Downshifting for these hills bothers me, because no other vehicle I own requires me to do so. None of them are that steep, and everything else will easily top every one of them in top gear. Sure, I have to downshift if I want to drop out and pass. Occasionally I have to downshift if I want to maintain an exact speed, but I won't lose more than 2-3 mph if I hold top gear. With the Jeep, I've gradually just stopped using top gear at all, because it doesn't serve any useful purpose. Even when I can run 6th gear, I get better fuel economy in 5th.

The problem is any speed I can actually run in 6th gear is just too low for the gear. I'm already lugging a little in 5th gear, which is why I have to downshift all the way to 4th so often. I've even had to catch 3rd just to get up a hill that everything else I own would top in its second from top gear.

I just wish it wasn't so expensive and involved to change the final drive ratio to something reasonable.

 

[PatrickR]

I don't know why there's so much hate for the gearing. I've got a sport s on 33s and I am cruising in 6th anytime I'm over about 50 (and it's flat). That equates to 1400ish rpm, and that's certainly not lugging it.

 

[grimmjeeper]

I don't know why there's so much hate for the gearing. I've got a sport s on 33s and I am cruising in 6th anytime I'm over about 50 (and it's flat). That equates to 1400ish rpm, and that's certainly not lugging it.

Do an experiment. Fill up your Jeep and run a highway loop in 6th gear back to the gas station. Fill up again. Calculate your mileage. Then run the same loop but stay in 5th gear. Fill up again. Calculate your mileage.

I think you'll be surprised at the result.

 

[PatrickR]

Do an experiment. Fill up your Jeep and run a highway loop in 6th gear back to the gas station. Fill up again. Calculate your mileage. Then run the same loop but stay in 5th gear. Fill up again. Calculate your mileage.

I think you'll be surprised at the result.

I've done that using the onboard mileage calculator and found an advantage to 6th... Now I don't trust the onboard calculator to be accurate in an absolute sense, but I expect it to be accurate in a relative sense.

To be clear, final drive ratio in 5th is already taller than 5th in my mustang I had before, so it doesn't really need a double overdrive, but it does help with fuel economy slightly.

 

[Ridgway Jeeper]

I just wish it wasn't so expensive and involved to change the final drive ratio to something reasonable.

This is why I stepped up to the Rubicon from the start. The 6MT and 3.45 ratio is talked about a lot on the forum, it just isn't a good fit. I see people spending all they saved on the Rubi package on mods it comes with all the time.

 

[Micky]

1. its a stick shift. you shift into different gears for different situations. accelerating, moving at a steady flat speed, climbing.... etc...
2. Part of the fun of a stick shift, it YOU control how the car revs and accelerates.

I could drive in 4th gear and climb beatifully but rev higher at speed and use for gas. or use 6th on flat terrain and have a smooth lowish rev at speed and have good gas mileage. or use 6th for trying to drive at speed on a climb and watch the car struggle with too high a gear. You control the gearing and can take advantage of the gears that work with the situation.

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