Fuel mileage diesel vs gas

[dennislanier]

I have seen some information on another forum that there is only about 1 to 2 miles per gallon increase in mileage for a diesel versus the V10 Ford. Does that seem to be the consensus? With the extra cost of diesel fuel these days, what is the major advantage for a Super C with diesel engine? I suppose if you travel a lot in the mountains it might make a difference. Someone please enlighten me.

[ronfisherman]

path1 wrote:
You just can't let "gomer" under your hood of a diesel.

I don't think I want just anyone under the hood of my late model gas vehicles either.

[Handbasket]

Y'all haven't mentioned one issue... the diesel carries 'tallest dog at the campfire' bragging rights. IMO, this is more important to some folks than foot-pounds will ever be.

Jim, "The real world is not user-friendly."

[path1]

Here is something you might want to consider... When traveling and something happens with the gas rig and it needs a mechanic, I don't worry to much about taking it to some dealer on the road that we don't know. Fixing whatever is wrong is usually no big deal and usually many mechanics are familiar with gas rigs. But with our diesel totally different story. You just can't let "gomer" under your hood of a diesel. One thing might be wrong in fuel system and they start naming what needs to be replaced in ENTIRE fuel system and seeing dollar signs in their eyes.
And I don't care about being the first one on top of the hill. I just want to get up the hill many times. IMO

[AprilWhine]

Here's some real world numbers for the diesel: We just completed a 9,800 mile trip, including lots of really bad roads, and the overall fuel economy averaged 13.93 mpg. During the trip, we towed a Mini Clubman loaded with 25 gallons of diesel on the safari rack and other stuff inside. We drove from Las Vegas to Iowa to Montana, through the Yukon Territory, did the Alaska circle, then back to Seattle. Along the way, we could out run any of the gassers or diesel pushers on the hills. Gassers because they loose power at altitude, DPs suffered from power to weight ration.

IMO, get the one you want, you can always justify it later. 😉

[rjstractor]

In many of the gas vs. diesel discussions, you need to consider which specific chassis you are considering. With the Ford E series you will get a mileage increase but not a huge one. Power will be around the same, since both the 7.3 and 6.0 Powerstroke engines are derated to in the neighborhood of 250 hp/440 torque. The V10 IIRC is 305/425. Longevity is not a factor because the coach should fall apart long before the engine,and both the 7.3 PS and V10 are durable, long lasting engines. The 6.0, although better in the E series than the pickups, has reliability issues that would erase it from contention if I were shopping.

[pnichols]

dennislanier wrote:
Very interesting discussion, folks. You keep writing and I'll keep reading. Thanks.

If you haven't already, you might want to click on the link I posted above leading to another long discussion on diesel power versus gasoline power.

That discussion is (almost) very appropriately titled "Horsepower is horsepower?" ... although IMHO, the question mark in the title should be removed. Read through all the pages to see what I mean.

[ronfisherman]

pianotuna wrote:
Hi,

I don't follow your math. If a gas engine gets 10 mpg (I get 11 mpg) and the diesel 12 that is only a 17% advantage. Then there is the cost of additives for each tank of diesel burned.

ronfisherman wrote:
Comparing fuel cost. When diesel is $4.00 per gallon. Gas has to be below $3.20 to have a price advantage over diesel. On Chevy based MH's on the C5500 Super C's. There is more than a 2 MPG difference on same size/model MH's.

The fuel mileage on Kodiak based Super C's is 8.0 for gas and 10.0 for Diesel.

[dahkota]

I have looked at almost every C available. They all have a tow limit of 5K lbs. I have found a few diesel Cs (not sprinter based). They have a tow limit of 10K or more. I have also noticed that the GVW is a lot higher in the diesels, allowing for more stuff. So, with a diesel, I can carry more and tow more.

[dennislanier]

Very interesting discussion, folks. You keep writing and I'll keep reading. Thanks.

[pianotuna]

Hi,

I don't follow your math. If a gas engine gets 10 mpg (I get 11 mpg) and the diesel 12 that is only a 17% advantage. Then there is the cost of additives for each tank of diesel burned.

ronfisherman wrote:
Comparing fuel cost. When diesel is $4.00 per gallon. Gas has to be below $3.20 to have a price advantage over diesel. On Chevy based MH's on the C5500 Super C's. There is more than a 2 MPG difference on same size/model MH's.

[ronfisherman]

Comparing fuel cost. When diesel is $4.00 per gallon. Gas has to be below $3.20 to have a price advantage over diesel. On Chevy based MH's on the C5500 Super C's. There is more than a 2 MPG difference on same size/model MH's.

Reasons to have a Diesel.
1. More power.
2. Better fuel MPG.
3. Longer distance between fuel stops.
4. Longer oil change miles 15,000 to 5,000.
5. Little to few problems with fuel storage for extended times.
6. Longer engine life.
7. Higher resale value.

Reasons to not have a Diesel.
1. Initial cost.

[carringb]

PS my V10 is not stock so it's not a totally fair comparison. But the mods don't seem to have hurt longevity except for spark plugs which I had to upgrade to iridium because the platinum plugs were wearing fast due to the programmer.

[carringb]

Artum Snowbird wrote:
A Super C, with a V10... yup, let's head to the mountains and see where you end up in the slow lane. Sure, you will coast along near the coast and manage to make most grades, but if you plan to get out there in the hills, expect power to drop, except for turbo boosted engines, and already MPG has fallen..

But, if you want to run only a few thousand miles a year, your V10 is really a good engine and you will be happy with the $$$ saved.

Well I only put on about 35,000 miles a year on my V10 so I'm only at 360,000. Even when I'm pulling 15,000 pounds I'm happy with the power (that's not saying I wouldn't be happier with more LOL). I used to drive a mix of dura max and cummins 6.7l at work and I was actually surprised that they didn't pull harder then the V10... they just did it with less RPM. Granted they were all cab/chassis so teu don't make the same power as the same diesel pickup. I think it's also telling that Ford offers the V10 in the f650 but not the Ford diesel. If I ever did go bigger, I would go bigger buy I'd do it right and get a Freighliner m2. That is a nice truck!

[pianotuna]

Hi,

There is at least one documented case of a V-10 going 1 million miles (istr in an RV).

Diesel wins on torque. Gas wins on over all price.

I've had both and would not go diesel, even though in Canada there is a price advantage on the fuel.

[fortytwo]

Crickeydog, my 40+ years of reading & experience is consistent with yours up to the introduction of the V-10 gas engine. From that point on it became a matter of personal preference up to about 27,000 CGVW. Above that diesel is the only option. The V-10, with synthetic fluids, has durability for RV'ers equivalent to diesel engines - the owner gets tired of the coach, or chooses not to do the necessary refurbishment well before the engine is an issue. Before the V-10 big blocks required a major overhaul at 80-100k miles .

10 years ago diesel was cheap compared to gas. Today prices are reversed.

For 27,000 and below the real difference is pay $30k up front for the diesel, or pay it over the next 10 years for the gasser.

Above 27,000 CGVW it's a completely different world: stronger frames enable different ride systems and deluxe features and capacity simply not possible otherwise.

I downsized 2 years ago, and am encountering a significant number of folks who either have, or are investigating, exchanging the big rigs for 30' and below. In most cases, like mine, it's an age thing and/or a desire to get back to places (state parks, forest campgrounds, etc) big rigs simply can't go, or are competing for only a couple of sites per park. Then the paradox: big rigs have big tanks - small rigs have small tanks. Just the opposite of what's needed in parks with less robust facilities. But then, it's just a matter of expectations: my first rig had 10 gallons fresh water, a wobble pump, no holding tank, no bath, and only 5 gallons of propane -- and we loved it. Engine technology today will enable diesel engines to be downsized to give RV'ers a personal choice.

IMHO the issue of gas vs diesel is not the relevant issue any more. Your desired RV lifestyle can be had with either.

RV History:
10 foot Cabover P/U camper - Ford 352 V8 - 10 years - 100k miles
23 foot Class A - Dodge 413 V8 - 20 years - 95k miles
20 foot Class B - Ford 460 V8 - 1 year - 10k miles
20 foot Class B+ - Dodge 360 - 3 years - 40k miles (130k miles on eng)
35 foot Class A - Ford V-10 - 12 years - 130k miles
24 foot Class C - Mercedes V6 diesel - 2 years -17k miles (current)