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-   -   GC CRD 2012 RPM too high? (http://www.jeepgarage.org/f157/gc-crd-2012-rpm-too-high-34456.html)

wimbers 01-21-2012 02:05 PM

GC CRD 2012 RPM too high?
 
Hi,
I test drove a GC 3.0 CRD overland last week, and apart from finding almost everything fantastic about it, i was really disappointed by it doing 2500RPM at 120 KMh on the highway. what's that about? it should be somewhere around 1800 at that speed or not?
i checked everything and it was really in Drive, not in 4, not in sports mode..
I drove it up and down a stretch of 25km of highway and the rpm would not go down. This is really a deal breaker for me as the rpm's and accompanied noise are more than the previous version. Dealer could not tell if this was normal or not.

any experiences from CRD drivers and RPM on higher european speeds (120 to 140 kmh?

I'm doing a lot of my mileage in Germany, so it must be comfortable at 85miles (145kmh) per hour as well. The old (2007) version is.

52233 01-24-2012 10:45 AM

Re: GC CRD 2012 RPM too high?
 
Quote:

Originally Posted by wimbers (Post 557480)
Hi,
I test drove a GC 3.0 CRD overland last week, and apart from finding almost everything fantastic about it, i was really disappointed by it doing 2500RPM at 120 KMh on the highway. what's that about? it should be somewhere around 1800 at that speed or not?
i checked everything and it was really in Drive, not in 4, not in sports mode..
I drove it up and down a stretch of 25km of highway and the rpm would not go down. This is really a deal breaker for me as the rpm's and accompanied noise are more than the previous version. Dealer could not tell if this was normal or not.

any experiences from CRD drivers and RPM on higher european speeds (120 to 140 kmh?

I'm doing a lot of my mileage in Germany, so it must be comfortable at 85miles (145kmh) per hour as well. The old (2007) version is.


my 2007 3.0 benz CRD does 2500 rpm at 120 km, this is too high and they should have added another gear for the 2012 models for milage at least!

wimbers 01-24-2012 03:20 PM

Re: GC CRD 2012 RPM too high?
 
ok, thanks for the info.
if this is still the case it makes a lot of sense to start working on the 8-speed box for the crd as soon as possible!
anyone with experience on the WK2 CRD?

WK2Diesel 02-23-2012 08:39 AM

Re: GC CRD 2012 RPM too high?
 
the futur 8 speed transmission have the same final ratio 0.67... no point to have 8 speed...

Deserthucker 02-24-2012 08:02 AM

Re: GC CRD 2012 RPM too high?
 
They may change the dif ratio

WK2Diesel 02-24-2012 09:02 AM

Re: GC CRD 2012 RPM too high?
 
That would be great!

Deserthucker 02-24-2012 09:11 AM

Re: GC CRD 2012 RPM too high?
 
I am only guessing, would be pointless having an 8spd ad not modding the rest of the drive train.

OutbackJeeper 07-19-2012 06:55 AM

Re: GC CRD 2012 RPM too high?
 
Isnt there a different Final Drive Ratio of you have Quadra-Trac

This is kifted from a Australian Jeep Website
http://www.jeep.com.au/compare-models-grand-cherokee

Quadra-DriveŽ II active full-time 4WD

Rear Electronic Limited Slip Differential (ELSD), 3.45 axle ratio, 230mm rear axle

Swampy 07-19-2012 06:47 PM

Re: GC CRD 2012 RPM too high?
 
I've noticed also that the CRD seems to rev higher than what I would have expected for a diesel, even when speeding up, it revs higher through the gears. I would have thought lower revs because of all that torque.

On the plus side though, it seems to make towing effortless when towing large items ie boat, at about 90 - 95 kms an hour.

When cruising at high speed I think that that the vehicle is still quiet, so not really an issue.

savvas 07-19-2012 09:19 PM

Re: GC CRD 2012 RPM too high?
 
The CRD gets 550Nm between 1800 and 2800 rpm, so even at 2500rpm your still in max torque range. kW's are higher up the range (max 177 at 4800rpm), so the sweetest combination where highest torque intersects the highest available point of power is at the 2500-2800 rpm range. After that kW is increasing, but torque is falling away.

The ELSD and standard diff on the CRD are both 3.45 ratio, 230mm.

I had the opportunity to cruise for a little while at 155km/h and it's far from being uncomfortable or noisy at that speed. I didnt notice what rpm it was doing though.

Clubby360 07-19-2012 11:41 PM

Re: GC CRD 2012 RPM too high?
 
i can hardly hear my 2012 laredo at 100 to 120 kmh i reckon there is more engine noise driving around town between 30 to 50 kmh,it is such a beautiful cruiser does not bother me if it is sitting at 1800 or 2500 revs!.

Hickers 07-20-2012 01:30 AM

Re: GC CRD 2012 RPM too high?
 
don't let it stop you, most of our travels in our crd have been between 110 and 140 kph, if it wasn't for our restrictive speed laws it would be a great car to cruise in at even higher speeds. Its quiet and enough power in reserve to pass triple road trains and caravans with ease even when doing some fast travelling. Nice and quiet too, even on the gravel.


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