I know that Jeep gives the Trail Rated Patriot a "crawl ratio" of 19:1 and the non trail rated CVT2 a crawl ratio of 14:1. Does anyone know what the crawl ratio of the Patriot with the FD1 with the stick shift is? And does anyone know how that is calculated?

Thanks,

MJC

I know that Jeep gives the Trail Rated Patriot a "crawl ratio" of 19:1 and the non trail rated CVT2 a crawl ratio of 14:1. Does anyone know what the crawl ratio of the Patriot with the FD1 with the stick shift is? And does anyone know how that is calculated?

Thanks,

MJC


Good question. I would also like to know this as I have a Patriot North on order (FDI). I did a fair amount of searching and cannot find the answer either. :confused:

This is a good question, I was talking to someone the other day about this exact same subject. Please, someone find out. I really want to know.

Transmission - 1st gear ratio (or lowest on CVT) x Final drive ratio = Crawl ratio

T-355 5-speed: 3.77 x 4.12 = 15.53

CVT: 2.349 x 6.12 = 14.37


CVT w O/R Crawl Ratio: 2.349 x 8.135 = 19.11

I'm sorry, but did you just tell us the ratio of the FDI If you did, it went straight over my head.

Yes.
FDI: T-355 5-speed: 3.77 x 4.12 = 15.53

CVT: 2.349 x 6.12 = 14.37



FDII: CVT w O/R Crawl Ratio: 2.349 x 8.135 = 19.11

He said your "rear end" ratio x your "granny gear" = Crawl Ratio

For Instance the Jeep Liberty 4x4 Auto is:

3(1st gear) x 3.73(diff ratio) x2.72(transfercase in 4LO) x2(torque converter) = 60.8 Crawl Ratio

Yes.
FDI: T-355 5-speed: 3.77 x 4.12 = 15.53

CVT: 2.349 x 6.12 = 14.37



FDII: CVT w O/R Crawl Ratio: 2.349 x 8.135 = 19.11

Thanks, I lack the knowledge of gear ratio lingo, but now I understand.

Some numbers I've crunched, hope this helps, and that everything lines up!

Low Crawl Ratio OVL top ratio axle ratio rpm@60 MPH
5spd 15.5 : 1 3.34 : 1 4.12 2464
FD 1 14.37 2.41 6.12 1787
FD 2 19.1 3.21 8.13 2308
CherokeeAuto low 27:1 2.66 3.55 2050?
high 9.94:1

Hope this helps, I was looking at RPM at cruise speeds vs. longevity, and was wondering how they made the difference --- looks like axle ratios...... And I threw in a Cherokee for comparison - Wrangler non-Rubicon would be similar.

Wow, that's very interesting. this should mean that the FD 1 SHOULD get better gas mileage than the 5 speed stick while cruising at 60 MPH and loafing along at 1787 rpm. What is really surprising to me is that the FD2 churning at 2308 rpm is still running slower than the 5 speed which is at 2464 rpm.

(I'm getting a headache!)