Originally Posted by 10Xk
Using diesel power mag. MPG figures (notice favoring diesel) you will get on average a extra 42 miles per tank of diesel. Towing, it's a mid size, Unibody SUV, for reference a midsize body on frame (how trucks are built) 4Runner tow rating similar to GC. Once Toyota adopted the J2807 Tow Standard their towing capacity dropped.
???? Notice professional reviews.
"although we never reached the 24-mpg highway rating found on the window sticker (or even the 20-mpg city rating) during our tests, the Grand Cherokee 3.0L CRD never dipped below 17 mpg-quite good for a powerful midsize SUV, especially when compared with the EPA ratings of the non-SRT gasoline V-8 options (15 mpg combined city/highway)."
"FUEL ECONOMY: EPA city/highway driving: 20/24 mpg C/D observed: 17 mpg"
"Mediocre fuel economy for a diesel, subpar braking distances"
That's great they can get 17mpg with a brand new CRD WK while beating the snot out of it. Notice all those tests include numerous acceleration tests, panic stops, hill climbs and off roading. Of course under those conditions any vehicle will not get near the EPA sticker whether it's a diesel or a gasser. Please also note the writers never said their intention was to maximize fuel economy (which you are linking articles that don't make this intention - instead test drives). I race with some well known car review writers and they will are simple there to beat the snot out of the test cars (if you want to read up on a diesel review where they attempt to maximize fuel economy read up on the Audi TDI 48 coast-to-coast challenge; or VW's 78mpg Passat coast-to-coast challenge as well). One article you quoted is a joke as they were comparing their CRD's actual test drive MPG in simply to the EPA sticker for the Hemi. Yeah - that's a fair comparison. FWIW: EPA test is on a dyno with friction added to the rollers as "drag" and they accelerate often at low rpms and don't push the engines (in other words not reliable in any sense).
Now if only only car rag did a test of both the CRD and Hemi under the same circumstances that would be relevant. Wait someone did. C&D which you linked only the CRD First Test where they got 17 mpg. Well C&D also did the Hemi (and noted it in the same article which you didn't mention) where the 2007 Hemi only got 12 mpg in those tests. So let's analyze the best data we have. 12-17 = 5 mpg difference. Not much it would seem but when the numbers are that low it's actually a big deal. So 5 mpg compared to 12 mpg is a 58% difference meaning the CRD got 58% better mpg under C&Ds same tests than the Hemi. That's quite a delta and much more fair than simply comparing a road test to an EPA sticker. (C&D Hemi test: http://www.caranddriver.com/reviews/...-roadin-page-2
So mpg comparisons have to be done under similar circumstances or they are completely irrelevant. EPA is also a terrible test as well as we know how faulty they are. Still don't trust me...check out Feully.com for the 2007 and 2008 model years and what owners are getting. Please throw out the outliers (like the 2008 Hemi 35 mpg number which is not even close to actual even for a diesel).
You can use filters to filter out the v8 (non flex-fuel) and the CRD for comparisons. Doing this shows:
- The CRD average mpg for the 2007 is 18-24 mpg with the mean in the 23-24 mpg range,
- The v8 is from 8-18 mpg with the mean closer to 14 mpg.
- The v6 gets 15-20 mpg with the mean closer to 17 mpg.
Personally I get 23-24 mpg when driving normally at 65 mph (calculated based on actual fuel receipts and trip mileage as I have to submit for reimbursement). So when I tow I get from 17-20 mpg depending on the terrain and wind doing 65 mph. The worst ever mpg I've gotten was 14.7 mpg towing my open trailer with bikes, canopies, coolers strapped to it into a slight headwind on Route 99 through south central KS (hilly) with 5 adults and a 40 lb beagle / doberman mix (he's a cutie). My normal mpg when at home which includes a 50/50 mix of city / highway is 20 mpg. I've got 100k on my CRD which diesels get better mpg once they get over 50k miles as the engine is worn in like a good shoe. Please also note my CRD is basically stock (no GDE tune or exhaust, intake, DPF delete, etc.).
Another topic I hear is the CRD must be really slow...
4 wheeler CRD review
"We had a chance to drive both a Hemi-powered WK and the CRD, and the differences in acceleration ain't like the proverbial tortoise and hare. The butt-dyno says the diesel we tested had the edge from zero to 30 mph. With 376 lb-ft on tap from 1,600 to 2,800 rpm, it ought to, but whatever the Hemi gains further up the rpm range, the diesel isn't as far behind as you would expect. It does tend to get a bit winded at higher rpm, but like many Euro-diesels, it does a pretty good gasser imitation."
In the End
Essentially - different strokes / different folks. A lot of people think diesels don't get good mpg compared to the usually higher price of fuel or the higher sticker price. Plus they are fearful of the "smell" of diesel fuel and finding a station. A lot of these fears are unfounded and with an educated owner you often don't run into these problems. There's also the fearmongers who spread misinformation about how expensive they are to maintain and if something breaks it costs $x million. They are full of bull**** as these engines are pretty stout as they've been in operation for over a decade and sold ROW in many Jeeps, Chryslers, Benzes. Yes things do go wrong with the CRD but they are well known and fixed easily and quite inexpensively. Glow plugs don't cost $200 a piece, the swirl motor can fail due to an oil leak from a faulty intake tube but can be fixed with a $.05 resistor. These engines are not that common at Jeep dealers so you may get the run around and there are suckers who will pay and not educate themselves and complain (if only they did their research). The biggest problems I've had with my CRD is repairs required by the failure of Jeep parts the engine (f&r elsd solenoids, alternator, window regulator, blown shocks/struts, seat tear and steering wheel wrap discoloration).
To get around these "fears":
- read up on my FAQ
on known issues with the CRD or this forum.
- don't read anything on the Internet and assume it's true.
- don't trust what you read in a vacuum (like 17 mpg tests on the CRD which are not indicative of it's true mpg potential when driven without a lead foot).
- get gasbuddy on your phone to find diesel stations and shop around the price (I often see $0.20 differences in the cost with stations just a few miles away).
- buy a box of plastic food server mitts for refueling if you don't like touching the fuel filler nozzle (some are pretty dirty).
- learn that there are 2 kinds of diesel nozzles and the small one only works with the CRD (others are for big rigs who need ~ 100 gallons for a fill up).