[VIRGINIA GENTLEMAN]

After doing a little reading regarding the Grand Cherokee with the Hemi & mds
the specs Chrysler "recomends 89-octane" with "87-octane acceptable" Has it been detuned?

VG

 

[chasb]

Octane

In owners manual , it recommends 89 octane for the MDS system to perform to spec on the 5.7's.

Car also runds better all around

CB

 

[jjs]

After doing a little reading regarding the Grand Cherokee with the Hemi & mds
the specs Chrysler "recomends 89-octane" with "87-octane acceptable" Has it been detuned?

VG

I was under the impression our manual states that as well.

 

[jhelmuth]

... it does

 

[VIRGINIA GENTLEMAN]

What page? my 06 manual on page 246 says 89 for 5.7 with no mention of 87.

VG

 

[jjs]

What page? my 06 manual on page 246 says 89 for 5.7 with no mention of 87.

VG

Don't have it with me...will have to check.

 

[chasb]

89 only

Not 87

My 06 300c manual doesn't mention 87 either, It is the same engine however.

 

[jjs]

OK, checked my '05 manual this a.m.

Apologies for being mistaken...on page 250 it shows a little graphic for 87 and one for 89...thing is, the 87 graphic is for the 2.7L engine while the 89 is for the 3.5 and 5.7. One thing is that the manual does clearly state that premium is not recommended.

 

[VIRGINIA GENTLEMAN]

After a little more reading the Cherokee only has 330 HP not 340 like the C thats probably why they can run 87.

VG

 

[chasb]

My wife had a jeep before and likes them

Cant imagine her with 330 HP. She's got a lead foot with the Acura MDX as it is

 

[jeepgrady]

Guys, the Jeep, Durango, Ram, and "C" are all basically the same engine. The difference in the HP is related to different considerations such as the exhaust.

By no means is the Jeep de-tuned. The manual says it can run on 87-89, but the mfg. recommends 89 for the best performance. This is really the same as the "C". She will also run on 87, however, for best performance, you need 89.

In the owners manuals for both vehicles, it is very explicit that you should not use 93 octane.

 

[kevenj]

The jeep is the only one with MDS like the 300c, the Ram and durango do not have this feature but I agree the difference in power ratings is most likely due to exhaust, or simply so that the jeep does not have a higher rating than a 300c..... curiously the Ram 1500 is rated at 345 hp but 'only' 375 lb/ft torque. I can say with certainty that for a 5600 lb vehicle my brother's '04 Ram 1500 4x4 is not lacking in the torque department though!

 

[HaTaX]

For 2006, MDS has been brought to both the Durango and the Ram.. Just took a few years to get it in there....

Hopefully it won't kill the resale for the previous generations with the HEMI.