Gas Vs Diesel - any mileage info anyone can share?

[billmoore]

David, I normally would agree with you, but I've been really impressed with everything I've read about the 3.5L EcoBoost. It has a torque curve more like a diesel than a gas engine. 365 HP, 420 ft-lbs of torque, which is great, but the truly impressive spec is that its torque curve crosses 350 ft-lbs at 1400 rpms and stays above that mark until about 5500 rpms.



As you can see above, even the 6.2L can't touch it for towing torque.

As far as longevity, there are quite a few out there with over 100K miles already, but only time will tell if it can match the V8...

[david]

Thanks for posting the curves.

I certainly agree that the EB is impressive with more than 400 ft lbs of torque at 2,000 rpm. But those 400 ft lbs will generate a lot of stress and heat in a 3.5 liter engine. I will bet that the 5.0 liter engine has twice as much bearing and piston area to take that stress as the EB. Also the exhaust gas temperature will be high with that much extra air being pumped in and burned. But I suspect Ford used the best metallurgy for the valves to deal with that heat.

Yes time will tell how that engine holds up under heavy towing loads.

David

[dh50]

Pretty impressive, David.  This proboard is privileged to have you smart chaps sharing your expertise.

[swbc150]

I still feel more comfortable with the SuperDuty Truck and the Diesel option I did look at but stayed with the gasser.

 

[stevesanders]

I have two VW Golf-series diesels.  Both have trip computers built-in so I've got lots of figures.

My 2010 Golf couple with the 6 speed manual transmission is the tow vehicle for our 6.0.  It's a fabulous tow vehicle.  Plenty of torque and control.  MPG with the camper is 28 - 34.  MPG in suburban congestion is about 38.  Average trip MPG without the camper is about 44.  On one trip from Birmingham to Orlando, I got just over 47 MPG both ways.  I would not hesitate to pull a 10.0 with the Golf TDI.

My wife has a 2012 Jetta Sport Wagon (aka. Golf Estate).  Since it has the "DSG" automated dual-clutch gear box, we don't tow with it.  It gets about 35 around town.  Last September we drove it to Las Vegas. The return trip was 1,800 miles or so in 27 hours at an average speed of 69 MPH and 42 MPG.

Neither of these cars use exhaust fluid, but they do have a complicated emissions system.  With about 45,000 miles on the wagon and 85,000 miles on the coupe, both emissions systems have been trouble free.  The Golf had a sensor go out early in its life, but it wasn't a big deal.  The cars have a 10,000 mile service interval, so the expensive oil change isn't that expensive because it isn't required very often.  So far, the only expensive service has been the 40,000 mile DSG transmission service and timing belt replacement around 85,000 (unless you feel lucky).

We bought the 2010 and liked it so much, we bought the 2012.  We have no regrets and would do it again.

[davidb]

I have another perspective on diesel vs gasoline which is mileage range, we tow our 6x15 toyhauler with a Toyota Tundra with the 4.7 liter engine, we get around 10-11mpg towing at 60-65mph.

The fuel capacity is 26 gallons and a quirk with the Tundras is the fuel light comes on when you get down to 6 gallons left in the tank, which means you really have enough fuel for about 250 miles, but it's a little nerve wracking wondering if you really have enough fuel or not.

The most distance I have squeezed was about 230 miles looking at the fuel warning light for 30 of those miles, it gets my wife very nervous!

Day one of our Louisiana to Colorado trips is always 900 miles in 16 hours (that's why we go 65mph) which means four to five fuel stops, the Grand Cherokee diesel would definitely get it down to around three stops but actually a stop every three hours is just about right for Dairy Queen/restroom/coffee/leg stretching.

I have heard quite a few reports of numerous fault lights coming on at random on the  Grand Cherokee diesels, no fun when on a multi day trip, especially on a weekend between Tucumcari NM and Amarillo TX!!

Happy travels
David and Alice

[billmoore]

That is why I love the 36 gallon tank on my F150. Fill it up and the trip computer says 650 miles to empty (although I only get about half that when towing)...

[pjcd]

I Have towed with gas and now own a diesel, I would say there is no comparison, especially when it comes to towing up hill, (I owned a 22H Nash). My old Dodge, ( I bought new ) had a 5.9 V8, when towing it got about 9 mpg, it had the 4.10 rear end and couldn't tow up hill to save it self. I now have a 2011 chevy diesel 6.6 and it can actually accelerate up hill while towing, and I'm getting 15 - 17 mpg. The service life of the engine, (in fleet use ) is over 200,000 miles, I don't think you'll see those kind of numbers in a gasser. however there's a premium price you pay for that.

[whoofit]

Just some factoids on the F-150's.

In 2015 over 33% of trucks were sold with the 5.0. The rest are combined with all other engines.
In 2018 Ford has announced it will offer the 5.0 Ecoboost.

Looks like there is no denying the V8 is here to stay. That V8 EB will be a monster.

[pjcd]

As for towing, diesel is the way to go, more then half of all HD pick up trucks sold are diesel. Light duty truck are just starting to introduce smaller diesels which BTW have been manufactured by all the major car copies for decades, just not sold in this country.

[oregoncamper]

We have a CL13BHB with the off road package, which puts it a lot higher off the road, and therefore cuts mileage, I'm sure. Plus we have the older flatter front profile. How much that matters, who knows? We started pulling it with an older Acura MDX rated for 3500 pounds. We ususally drive around 55. Mileage went from 22 without the trailer to about 12 with. It handled mountain passes reasonably well, but it felt like we were abusing it. We traded that in for a 2007 ML320 CDI (this was the diesel before the new additive - it is still cleaner than old diesels, no smoke, pretty quiet, and smells like chlorine, not diesel). With this, our mileage goes from 26 to 16 with towing at 55, so still about a 10 mpg hit. The big difference is that it doesn't even know it is pulling anything and laughs at steep passes. It is a small SUV that fits well in our small garage. A lot of the newer diesels, including the MLs, now come with no spare because the space is taken up by the urea tank. Given where we travel, this was unacceptable. We even replaced the mini spare with a full size one. It still fits by leaving the cover elevated a little in the back compartment. We have been very happy with our choice. Any new diesel was out of our price range, but hopefully we can keep this one running a long time. The main issues will be electronic, I'm sure.