RPM v. KPH

My Pat usually runs just under 2000 RPM, usually bewteen 1800 and 1900, going 100 KPH, which is equivalent to approx. 62 MPH.

 

My Pat usually runs just under 2000 RPM, usually bewteen 1800 and 1900, going 100 KPH, which is equivalent to approx. 62 MPH.

mine also

 

sounds about right
i am right around 2500 at 60mph on my FDII

 

From an old thread:
45mph - 1850rpm
50mph - 2050rpm
55mph - 2250rpm
60mph - 2500rpm
65mph - 2650rpm
70mph - 2900rpm

http://www.jeeppatriot.com/forum/showthread.php?p=135068#post135068

 

480Kreepin and Kgaus,
That's the difference between the 2x4 and FDI, and the FDII.

 

so when you accelerate from 1st to 2nd gear in the FDI or FDII you often hit 3000 rpm?

 

I have no idea. The CVT doesn't change gears to tell.

Sent from my DROID X2 using AutoGuide.Com Free App

 

FDI 4x4 running under 2000 at 60-65mph usually at 2000 when doing 70

 

Sometimes mine gets to around 3,000 before it changes to a higher ratio, but usually I try to keep it around 2,000-2,200. When I keep it at 2,000 or less, I seem to get close to 23 MPG in the city. Only problem is its hard to drive that way all the time

 

OK Then......

2500 at 60 seems about right. Thanks for the confirmation.

 

Sounds about right to me to, depending on if on level or not.

Mine jumps over 5K RPM often on acceleration, and will stay high if you stay on the gas, but if you let off slightly as you near the speed you want (like passing or pulling onto the highway) the RPMs will drop noticeably and you will maintain speed.

CVT takes a little getting used to, but now that I'm used to it I prefer it over the regular auto-trans.

 

The FDII has 8.32 axle ratio or.something like that so it will rev higher than other patriots or even most other vehicles. It was concerning to me the first time I test drove the FDII. But now I just drive at 100 km/h or 105 km/h to improve my fuel consumption.
I wonder why the FDII doesn't have an over drive like the FDI seems to have.

 

FDII doesn't have an overdrive like FDI because they use the exact same transmission, but different axle ratio's

 

Interesting to see these numbers, so thanks for sharing.

I have MT in mine. At 60mph I am running about 2200-2300

 

The FDI has a higher axel ratio than the 5 speed but the FDI revs lower at highway speed. So if it has an overdrive program why can't they put something like it in the FDII? Axel ratio shouldn't have anything that would restrict an overdrive program in the FDII.
Another thought is that the FDII does have an overdrive deal but because the axel ratio is so different from a FDI that the revs stay high anyway.

Just my thoughts.

 

CVTII



It must be the physical limitations of the gearing in the CVT then which is I believe the same transmission in FDI and FDII. It can handle the lower end but is already at it's limits on the high end. Which raises the question is the difference between the CVTII and CVTIIL a programming issue or are there physical differences?

 

Here's the ratios for the Patriots:

As you can see, the 5-speed does go as low as the FDII (15.53 vs 19.11), nor does it go as high as the FDII (3.34 vs 3.21). This explains what you are seeing. But none of them have a separate Overdrive per-se. Although technically 5th gear in the 5-spd is less than 1:1, so it is overdrive.

 

Here's the ratios for the Patriots:

I'm loving this chart! What was your source for the numbers? Some time ago I took the time to figure out the ratios of a FDII and I remember the numbers were difficult to find.


For giggles.... here are the Wranglers:

the 6 speed (NSG370) (I believe these are still correct for the 2012).

1st: 4.46
2nd: 2.61
3rd: 1.72
4th: 1.25
5th: 1.00
6th: 0.84
R: 4.06

5 speed auto (2012 Wrangler)
1st: 3.59
2nd: 2.19
3rd: 1.41
4th: 1.00
5th: 0.83
R: 3.16

On the Wrangler you have three axle ratios 3.27, 3.73, or 4.10.

So in a manual Wrangler you have the lowest gear option (excluding low range) of 14.58, 16.64 or 18.29.

In an auto you have 11.74, 13.39 or 14.72. The auto can get away with higher gears due to the torque converter.

So FDII is geared LOWER than a Rubicon equipped with an automatic and very slightly lower than a Rubicon equipped with a manual. Do you think that 19:1 was just randomly chosen, or is that about as low as they can go without the consumers crying about it on the street?

Now, just because I have it up, lets factor in low range (2.73 in non rubicon's, 4.0 in the Rubicon).

Low range Rubicon manual: 73.16
Low range Rubicon auto: 58.88
Low range non-Rubicon manual: 39.8 or 45.43
Low range non-Rubicon auto: 32.05 or 36.55


You start complicating things with tire size though.
Rubicon has 32.1 inch tires, FDII has what.... 27.2 inch tires?

A manual rubicon in low range 1st gear at 750 rpm is moving at about 86 feet per minute (1 mph). To go 10 mph is 7,656 rpm.
A manual rubicon in high range 1st gear at 750 rpm is moving at about 345 feet per minute (4 mph). To go 10 mph is 1,914 RPM.
A FDII in low at 750 rpm is moving at about 279 feet per minute (3 mph). To go 10 mph is 2,362 rpm.

So back to the original question, how many RPMs do you burn at 60 mph?
In FDII with a 27.2 inch tire it should be 2,377 rpm.
In a Rubicon manual high range 2,163 rpm.


So at the end of the day.... FDII is geared lower than a Rubicon if the Rubicon does not go into low range. Your gas milage suffers for it, but your off road performance gets a huge boost.

 

The transmissions in the FDI and FDII are identical. Just swap out different axles and change the programming.

 

Thanks UA_who



We posted about the same time. Thanks for explaining that. Apparently the differential is the major difference. I guess the program differences relate to shift points.

 

Shift points and limits on high low. In the FDI, the transmission goes throughout the entire range, as needed. In the FDII, the lower 33% or so is restricted under normal driving. When you shift it into LOW on the gear selector, that 33% becomes available, and the high end 33% is restricted. Essentially just sliding the range of possible gears down.

 

Here's my sources.
Given (just based on conversations on this board)
Transmissions:
a) 5-SPD manual is a T355 transmission
b) CVT is Jatco JF011E

5-spd ratios
http://www.vibratesoftware.com/html_help/2011/Chrysler/1997-2012_Chrysler_transmissions.htm#T355

CVT ratios
http://www.vibratesoftware.com/html_help/2011/Diagnosis/Reference/CVT_Transmissions.htm

Axle ratios (for 2011 model year)
http://www.vibratesoftware.com/html_help/2011/Chrysler/2011/2011_MK_Jeep_Compass-Patriot.htm


All of that is 2011 data. It looks like the axle ratios might have changed in 2011 from earlier models. But the transmissions didn't.

Doing the same comparison on the Wrangler gets much tougher. You have optional rear-end ratios, transfer case ratios, etc. Many more columns. But it could be fun to look at.

 

Seeing this, I would like to have the front diff from the FWD in my FDI.
A little bit more revs without being as low and thirsty as the FDII.

Just to complicate things, in Australia the FDI Compass has a highest gear ratio of 2.28 whereas the FDI Patriot is 2.41.
I'm not sure whether to believe this or not, given I've seen errors on the AUS Jeep website before?

 

According to the chart, it's 2.41 with a CVT and a 2.0L, and it is 2.28 with the CVT and 2.4L

 

Yeah I know, it's too much of a coincidence in my mind. But the 4x4 specs for the Compass and Patriot are clearly labelled at 2.28 and 2.41 respectively.
Mind you, Jeep AUS also state that we can tow 3300lbs braked without additional precautions, so go figure...?