Jeep GC V8 vs. V6

[MCDenny]

Thought I'd update this thread now that were back home, even though Tim already already ordered his new Jeep. 11,500 miles, probably 80% towing. 23,000 total miles on vehicle.

Jeep caused zero problems. I caused one problem, left window down and raccoon ate armrest. $225 to replace. Mother Nature caused one problem, dropping tree branch on our hood as we sat parked on the road shoulder in Florida. Hood is aluminum so can't be bumped out, must be replaced, $1380. Only service has been two oil changes, a safety recall to tighten a ground connection (that I didn't need, it was tight from factory) and a software update. I'm probably due for another software update now which I'll get done later at the next oil change. BTW, the car's computer tells you remaining oil life. It predicts 10-11,000 miles between changes based on my driving style.

I'd didn't keep gas receipts so don't know the exact actual mileage but the cars computer steadily showed 16 - 17 mpg when towing. 65 mph is my target towing speed on freeway. 75 is effortless to maintain but I like the better safety margin of 65.

We spent the month of April driving 5000 miles from Fl to west TX up through NM and CO, home on I80. Some driving in the mountains at Big Bend NP in TX and crossed the southern Rockies via a 9400' pass. Always could go as fast as I wanted (45-60 depending on curves). Trans temp is usually 203F, engine oil about 200F. On longest pulls trans only went up to 206F, oil about 230F, water temp gage rose slightly. I recall tach was in the 4000-5000 rpm range when climbing. Redline is 6400 so no big deal.

Overall I am very pleased with the Jeep so far.

[Burtim]

Update from the OP.

Just took delivery of the Jeep and love everthing about it so far. I have about 100 miles on it and its showing 17 MPG in mixed city/highway driving, using ECO and sport modes. Its a beautiful vehicle!

[Mike Magee]

Congratulations, and many happy miles with your new tug!

As I understand it, there's Eco on, or Eco off (push the button), or Sport mode (using shifter). Each successive mode is supposed to do the shift points a little differently than the previous one. Enjoy experimenting.

I had to put my purchase plans on hold for now (actually ordered it, then cancelled the order) due to possible changes in work circumstances.

[MCDenny]

Tim. Nothin' sweeter than a new car. Enjoy!

PS: just finished a whole tank of gas of around town driving. 21.3 mpg.

[MC1]

Congrats Tim... Jeeps just keep getting better and better.

[Burtim]

So, I did the trip. Just thought I would give you a followup and the results of towing a Casita 17SD halfway across the country with a 2014 Jeep GC using the 6 cylinder motor.

Executive summary: I love it.

Details:

(All MPG and distances as shown on the Jeep trip computer) Using Pennzoil synthetic lubricants in the Jeep. In all cases the trailer was loaded down and the fresh water tank full. Generally grey/black tanks were empty. Tire pressures at 40# tow vehicle, 65# on the Casita with Maxxis tires. I pretty much guaged my stress on the engine by using the Jeep temperature indicator. Never had the tachometer over 4500 RPM. Red line is 6500 I think. Casita wheel bearings checked with an electronic readout at never more than 125 degrees (and then, only in the Mohave desert part of the trip). Bearings seem to always be about 20 degrees warmer than the surrounding air.

Wednesday June 11: Drove to Ogallala, NE where we camped the first night. It was 416 miles total with some side trips. Maintained 60 MPH (could have went much faster but chose not to as I got use to the rig). The vehicle got 18 MPG on this leg. Engine temps were around 200 degrees and the transmission was always cooler. Ambient air was cool.

Thursday June 12: Drove to Salina, UT for our second night. Passed over the Vail pass and the San Rafael Swell. 671 miles. Maintained 60 MPH except on the steepest climbs where I slowed to 50 MPH as the engine temp rose to a peak of 230 degrees. In the hotter West parts of this leg, I allowed the engine temp. to rise to a peak of 240 degrees to maintain my speed on the highest climbs. The vehicle got 16 MPG on this leg. Ambient air was cool (East) to warm (West).

Friday June 13: Drove to Las Vegas, NV for the final leg of the trip out. 314 miles. Maintained 60 MPH. Got almost 17 MPG. The ambient air was hot.

Monday June 23: Left Las Vegas, NV for Quail Creek State Park in Utah. 214 miles. Got a bit better than 17 MPG maintaining 65 MPH. Ambient temperature was HOT! Engine temperatures never over 210 degrees.

Wednesday June 25: Left Quail Creek, UT for Dead Horse Point State Park, UT. 342 miles. Got 16 MPG maintaining 65 MPH but slowing to 55 on the highest climb. Allowed engine temperature to rise to 230-240 peak never allowing it to stay there for more than a few minutes. Ambient temperature was HOT!

Friday June 27: Left Dead Horse Point for Ogallala, NE. 567 miles. Got a bit better than 17 MPG maintaining 65 MPH again slowing to 55 on the highest climb. Allowed engine temperature to rise to 230-240 peak never allowing it to stay there for more than a few minutes. Ambient temperature was cool.

Really took advantage of the Jeep UConnect SXM weather features. In the middle of nowhere East of Denver we ran into tornado warnings. Without real humans in the local radio stations, we had no information and the satellite weather radar and warnings display saved the day. We parked at a rest stop in Julesburg, CO early and took a nap while the area ahead of us got pounded. Without the weather info., we would have no knowledge what was to the East of us.

Saturday June 28: Left Julesburg, CO and headed for Omaha. 344 miles. Got 18 MPG. The ambient air was warm.

All in all, I am pleased. The Casita is almost "like a shadow" behind the Jeep. I think 17-18 MPG meets with my desire for decent gas mileage while taking it all with me. That is understanding we were in some pretty high elevations and extended climbs a great deal of the time. I could have went faster, the engine had it. I never had a problem passing others, when I wanted to. I just chose to keep the temp's. under 240 degrees and be safe. Is that too high? Should I try to stress it more? I don't know. But I do know it performed well for me and I am delighted.

In my opinion, the 2014 Jeep Grand Cherokee with Pentastar 6 cylinder motor is an excellent tow vehicle.

YMMV.

[Mike Magee]

That's good to hear! But... don't tell me you didn't set the EVIC to monitor the transmission temperature as well? That is the number I am most concerned about when climbing long grades. The engine temp I don't worry about at all. The trans temp readout is one of the top features that draws me to the GC.

[Burtim]

Addendum to my previous post-

I used the manual shifting feature quite a bit on the trip to Las Vegas. On the trip back, I decided to use the normal automatic drive ECO mode most of the time. I only used manual on occasion as a brake on really steep downhills, especially with turns at the bottom. I ended up preferring to use the automatic drive ECO mode. If there is no long term stress on anything allowing the transmission to pick its own gear, I really like how smoothly it worked. When using cruise control, it actually downshifts nicely to maintain speed with engine braking on its own. I don't know how unique that is, but it made it easy for me. For an eight speed transmission, it didn't hunt around for gears much either. It stayed pretty much in a gear you would have picked had it been a manual tranny.

[Burtim]

Mike,

Yes. I watched the transmission temperature. It never went much above 204 or so degrees so I got tired of looking at it and assumed it wasn't a problem. It was always well below the engine temp. It does rise as the engine temp goes up, but never reaches anywhere near the same number unless, I suppose, you are keeping the engine hot for hours on end.

I am an instrument rated pilot, so I started the trip out including everything in my "scan" just as in an aircraft. When things stay the same or don't change much, I scan them less often.

[Jack Allen]

Tim, thanks for the excellent report. I'm always interested in any Jeep GC experiences as my 2011 with Hemi has over 67000 miles and I am concerned what I can replace it with when my extended warranty is close to running out. My first choice is another GC as I have had a great time with the one I have now. I do need the Hemi as I tow a 21' Escape at 4200# and I do hit all of the passes in the West. The new diesel looks promising as it has over 400# of torque. Did your door sticker say 40# in the tires? Did you use a IR temp gun to check wheel temps? I may start doing that instead of the back of my fingers.
That was some good long days you put in, at our age we're trying to stay under 300 if we can or at least under 500 miles per day.
Thanks again and keep the shiny side up.
Jack of AZ

[Burtim]

My door sticker says 34 pounds (I think). But I see 44 on the Michelin tires. So I filled them -10% than the tire sidewall number says because I have seen posts saying both use the number from the sticker and number from the tire. The tires were at 40 from the dealer. They do vary with temp and altitude on the EVIC display. I understand more tires are blown under inflated than over.

[Mike Magee]

Originally Posted by Burtim

Mike,

Yes. I watched the transmission temperature. It never went much above 204 or so degrees so I got tired of looking at it and assumed it wasn't a problem. It was always well below the engine temp. It does rise as the engine temp goes up, but never reaches anywhere near the same number unless, I suppose, you are keeping the engine hot for hours on end.

I am an instrument rated pilot, so I started the trip out including everything in my "scan" just as in an aircraft. When things stay the same or don't change much, I scan them less often.

All right!! When you can have 204* or less on a long climb at 50 mph, you have nothing to worry about. That is good to know!

I agree with you that having some extra tire pressure is best when towing.

Your addendum about eco mode is very interesting. I was guessing that it would shift too much or something (and get too hot) if not in sport mode. But it doesn't! The electronic controls just make things easy. It didn't seem to make any difference in fuel economy whether you made the shifting decisions or the Jeep made them, either.

[MCDenny]

Glad you think as much of your JGC as I do of mine. I did the same experimenting with manual shifting vs auto and came to the same conclusion, the automatic programming is just fine. This trans is much smarter than anything else I have ever driven. It knows not to up shift when you take your foot off the gas going downhill.


Denny Wolfe
Wanderingourway.wordpress.com

[Burtim]

That transmission is smart. It wouldn't let me shift down while descending sometimes either, without applying brakes and slowing down first. It knew shifting down would cause the engine to rev too high and would not allow it. It knew I was using the engine as the brakes at those times.