Diesel vs Gas Engine? Better MPG When Towing??

[JimandLinda]

If this thread is redundant or misplaced, please let me know.
Jim and I have our 2017 Classic on order with a mid December arrival. Our TV is also on order, but I *think* we could change it if it becomes clear we've made a mistake. We might tick some people off, lose our place in line, and perhaps forfeit a $500 deposit we put down.
My quandary is this: I was under the impression I needed to avoid a diesel due to its odors - I have MCS (multiple chemical sensitivity) and petroleum products are difficult for me. I assumed diesel would be worse. So we ordered a 2017 Chevy Silverado 2500HD after test driving a 1500 and felt pretty good about that. It's got tow capacity of 13,000 lbs and I knew we'd be well powered. The smell and added cost of diesel had me discount it as an option.
Sooooo ... this weekend we went to test drive a 2500HD at a local dealer just to be sure we liked the size and the ride. All they had was a 2500HD Duramax diesel, which we figured would still let us evaluate size.
The seemingly very knowledgable salesperson told us that the diesel had so much better horsepower and torque that it would virtually not see a reduction in MPG while towing. He said we could count on ~ 20 MPG with the diesel, and ~ 20 MPG with the gas engine too, but when we were towing the gas would drop to 8 - 10.
We ran some quick calculations and figure that it'll take us 6+ years to recoup the extra 9K the diesel would cost, but at the end of that time we'd have a diesel with 300K miles of life left (compared to a gas engine that was tired).
QUESTIONS:
1) Do you diesel folks feel they smell any worse than a gas engine either in the cab, under the cap (where I'll be storing some extra clothes) or around the vehicle?? I understand the DEF will make a difference, but a naysayer today told me that over time it might smell worse. Comments/thoughts?
2) Do you agree that the MPG will stay significantly higher with diesel compared to gas while towing??
3) Can you share what sort of MPG you get both towing and not with your gas and diesel 2500 or 250 trucks? The EPA doesn't rate the bigger vehicles and I want information!
THANK YOU for your help and guidance. Forgive me for a newbie question. You don't have to fret about being gentle in your answers - I'm fine with blunt. I just need advice regarding if we should change our order!
I suspect if we call tomorrow or Tuesday and revise our order it'll be possible still. I hate to not change it for fear of making folks irritated if it's the right thing to do. If it's a wash, then keeping it as is, is easiest and we'll have our TV before the Classic arrives.
-Linda

[slowmover]

Today's Diesel engines have a life expectancy of 250-350k miles according to industry standards. And that assumes majority highway miles.

Gasoline engines of today aren't really that much below this.

An AS is neither heavy nor difficult to pull. No real advantage to diesel pickups in one ton spec. Don't pay too much attention to those who really are unable to spec a vehicle close to intended use.

So long as diesel is no more than 50-cents per gallon greater in cost, it is more economical as it has a greater BTU content. Price variance can quickly make the diesel more expensive.

The rule of thumb is that towing a travel trailer is about a 40% MPG penalty from solo at the same speed and over the same terrain. Engine type hasn't anything to do with that.

The higher cylinder pressure of a diesel means it will slow less easily when loaded, or on a grade.

The days of genuinely economical diesel operation for these light duty trucks are in the past. The complexity of today's means a higher up front cost, and greater repair costs in the one tons. A trailer of 15k or greater in weight is when they come into their own.

As to sensitivity to combustion byproducts, diesel exhaust is much cleaner than ten years ago. Just as catalytic converters and fuel injection have cleaned up gasoline engine exhaust since the 1970s. I always found the latter to be worse than the former. But that is in the past.

I've used these trucks in commercial applications. And drive Class 8. Have been towing these trailers since 1973. Were I buying new today as strictly a vacationing RVer I'd choose gasoline.

The half ton diesels are closer to being a better choice.

But the ability of today's gasoline engines and 6,8,9-speed transmissions make the gap between gas and diesel almost moot.


1990 35' Silver Streak
2004 555 Cummins

[DaveMc]

I've been reading anything I can find try to answer the same question for myself. I've decided on gas because of:

Main use will be commuting and around town
Potential repair costs in the diesel I could afford

Mileage is better from what I've read on these forums with diesel, but mpg is not the same as when not towing. I've pondered the diesel longevity question a while, I suspect the that computer gremlins would cause me to get rid of the truck long before the engine was ready to quit...

Dave

[Countryboy59]

Either will do the job for you. I've had gas and Diesel engines and they all last over 300,000 miles with proper care and frequent oil changes. I ignore the 7500 mile recommendations for oil changes and do it more often. Remember a gas engine runs at a higher rpm (makes horsepower at higher rpm because of lower combustion pressure) and they're made for that. The fuel price bubble may not last either and diesel can go up higher than gas. Both fuels smell in my opinion and I prefer the smell of diesel but my wife hates it.
Luckily you won't have to worry about rust which destroys these trucks long before they ever wear out.

[Echelon73]

I have owned several diesels over the years (cars and trucks) and my 2014 Ram with all the emissions systems in place is much cleaner than all of the previous ones I have owned. With 45,000 miles on it the tail pipe shows no signs of soot and I have never seen any visible smoke. On start up there is a very slight odor, but really no worse than our gas vehicles. My wife's family has a history of lung issues and even she is happy with our diesel truck. The only downside for diesel in my opinion is smelly pump handles. I wear disposable gloves when fueling, so it is not an issue for me, but this is something to consider. The ability to use truck fueling lanes while towing makes up for that in my mind though. I will not get into which is best to own or tow with. That topic is too heavily debated on this forum. I will say that ours has been reliable and fairly inexpensive to drive so far and I love the huge amounts of torque and the exhaust braking feature while towing.

[Toutsi 1957]

Originally Posted by JimandLinda

If this thread is redundant or misplaced, please let me know.
Jim and I have our 2017 Classic on order with a mid December arrival. Our TV is also on order, but I *think* we could change it if it becomes clear we've made a mistake. We might tick some people off, lose our place in line, and perhaps forfeit a $500 deposit we put down.
My quandary is this: I was under the impression I needed to avoid a diesel due to its odors - I have MCS (multiple chemical sensitivity) and petroleum products are difficult for me. I assumed diesel would be worse. So we ordered a 2017 Chevy Silverado 2500HD after test driving a 1500 and felt pretty good about that. It's got tow capacity of 13,000 lbs and I knew we'd be well powered. The smell and added cost of diesel had me discount it as an option.
Sooooo ... this weekend we went to test drive a 2500HD at a local dealer just to be sure we liked the size and the ride. All they had was a 2500HD Duramax diesel, which we figured would still let us evaluate size.
The seemingly very knowledgable salesperson told us that the diesel had so much better horsepower and torque that it would virtually not see a reduction in MPG while towing. He said we could count on ~ 20 MPG with the diesel, and ~ 20 MPG with the gas engine too, but when we were towing the gas would drop to 8 - 10.
We ran some quick calculations and figure that it'll take us 6+ years to recoup the extra 9K the diesel would cost, but at the end of that time we'd have a diesel with 300K miles of life left (compared to a gas engine that was tired).
QUESTIONS:
1) Do you diesel folks feel they smell any worse than a gas engine either in the cab, under the cap (where I'll be storing some extra clothes) or around the vehicle?? I understand the DEF will make a difference, but a naysayer today told me that over time it might smell worse. Comments/thoughts?
2) Do you agree that the MPG will stay significantly higher with diesel compared to gas while towing??
3) Can you share what sort of MPG you get both towing and not with your gas and diesel 2500 or 250 trucks? The EPA doesn't rate the bigger vehicles and I want information!
THANK YOU for your help and guidance. Forgive me for a newbie question. You don't have to fret about being gentle in your answers - I'm fine with blunt. I just need advice regarding if we should change our order!
I suspect if we call tomorrow or Tuesday and revise our order it'll be possible still. I hate to not change it for fear of making folks irritated if it's the right thing to do. If it's a wash, then keeping it as is, is easiest and we'll have our TV before the Classic arrives.
-Linda

I own an AS 27FB and my TV is a Denali HD with Duramax/Alison. Empty I do 20 mpg, towing I do 13 both at 60 mph. I select the diesel for safety and acceleration power. The advantages of the diesel engine are:
1. The fuel consumption of a Diesel will be better than a gas engine by 20% in any configurations, towing or not towing.
2. The diesel engine provide much higher engine brake than any gas engine. Saving on brake maintenance if you use it.
3. There are no more bad smell or noise with diesel engines. These are past history.
4. The torque of a diesel engine is double the torque of a gas engine. This make the trips safer because you have much better acceleration than with a gas engine. This is very important when you enter into a highway.
5. If you buy your truck with the diesel you will have no regrets at all while you may have some with a gas engine.
All experience people and mechanics will tell you that having a Diesel engine makes economical logic if you do more than 25,000 miles a year.
If you have more questions let me know. Myself and Jacinthe love our Denali.

[JimandLinda]

Thanks all! I really appreciate your thoughts and recommendations. Jim and I are in heavy conversation here and plan to speak to our buyer to see if it's even a do-able thing to change our order at this point. I'd think the dealer would prefer to make another 8-9K in this sale, but our buyer will have to negotiate further, and we might have lost some power there...
I wish I had a crystal ball to know if we will drive >25K per year! I'd say it's possible, but until we are out and doing it I can't say for sure.
At least from these answers if we do get 'stuck' with the gas engine we'd ordered I don't think it'll be a wrong choice or a bad one, despite diesel being a better choice for a few different reasons. The cost is an issue for us -so I want to be mindful there as well...
Again - THANK YOU all for weighing in here.
- Linda

[LesMesa]

As part of your costs calculations, does the gas engine in the 2500HD require premium gas for towing, or is it just the 6.2 engine in the Denali that requires premium? Diesel is generally more expensive than regular, but cheaper than premium.

[greenflag]

Points well made by Toutsi 1957.
150,000 plus miles on my Duramax/Allison with no tailpipe soot. It still doesn't smell or smoke.

[Amsterdamer]

In a Chevy/GMC 2500, the Gas configuration is somewhat less desirable than the available counterpart in a 1500.

For Chevy and GMC -
The Gas 2500 only available with the 6.0L (380T/360HP) and six speed transmission.
the Gas 1500 is available with the 6.2L (460T/420HP) and eight speed transmission.

In a 2500, there will be a significant MPG penalty over the 1500 with a 6.2L while towing as well as while not towing.

The 6.2 engine in a 1500 does not have any MPG penalty over the 5.3, though it does burn premium.

The Diesel version of the 2500 is very efficient and capable, but I think the Gas version could use some of the power train improvements that are available in the 1/2 ton trucks.

[Starlight Mike]

diesel for all the stated reasons. I've had both and no comparison for towing.

[BillfromWI]

We tow at 2014 FC25FB with a 2016 GMC Duramax/Alison. We just returned from a 11,500 mile trip to Alaska. Average fuel economy was 12.9 MPG. But we started the trip with 3,546 miles on the truck. I check the mileage at every fill with a calculator. It was in the 11-12 range a the beginning 14-15 at the end. Based on this I expect to get about 16 towing in calm wind after it is finally fully broken in. I suspect you would see about the same performance with a 30.

A digression: My previous TV was a 2013 F150 3.5 Ecoboost gasoline engine. It had max tow and max payload which required 3.73 axles (more engine revs per mile). It made 14 MPG towing on three fills in its 18,000 mile life with me. 12 MPG and less was typical. Others claim much better mileage with this engine, I think the 3.73 axle ratio made a significant difference. I traded for the GMC because the Ford did not have enough payload capacity.

The Duramax/Alison is amazing to me. Turn on the exhaust brake, set the cruise at 65 or the speed limit, whichever is lower, and it maintains that speed up hill and down. I found that I could descend any grade we encountered without using brakes if by reducing the cruise set point--you just have to tell it what you want it to do. It is as quite as the Ford was (very quiet) and I don't notice any diesel odor. But the comment, above, about using rubber gloves to fuel is good advice.

I love this truck but I don't expect to ever recover the $8,000 cost of the diesel option in fuel savings. There are other reasons that are more important to me.

[dcasr]

Originally Posted by JimandLinda

If this thread is redundant or misplaced, please let me know.
Jim and I have our 2017 Classic on order with a mid December arrival. Our TV is also on order, but I *think* we could change it if it becomes clear we've made a mistake. We might tick some people off, lose our place in line, and perhaps forfeit a $500 deposit we put down.
My quandary is this: I was under the impression I needed to avoid a diesel due to its odors - I have MCS (multiple chemical sensitivity) and petroleum products are difficult for me. I assumed diesel would be worse. So we ordered a 2017 Chevy Silverado 2500HD after test driving a 1500 and felt pretty good about that. It's got tow capacity of 13,000 lbs and I knew we'd be well powered. The smell and added cost of diesel had me discount it as an option.
Sooooo ... this weekend we went to test drive a 2500HD at a local dealer just to be sure we liked the size and the ride. All they had was a 2500HD Duramax diesel, which we figured would still let us evaluate size.
The seemingly very knowledgable salesperson told us that the diesel had so much better horsepower and torque that it would virtually not see a reduction in MPG while towing. He said we could count on ~ 20 MPG with the diesel, and ~ 20 MPG with the gas engine too, but when we were towing the gas would drop to 8 - 10.
We ran some quick calculations and figure that it'll take us 6+ years to recoup the extra 9K the diesel would cost, but at the end of that time we'd have a diesel with 300K miles of life left (compared to a gas engine that was tired).
QUESTIONS:
1) Do you diesel folks feel they smell any worse than a gas engine either in the cab, under the cap (where I'll be storing some extra clothes) or around the vehicle?? I understand the DEF will make a difference, but a naysayer today told me that over time it might smell worse. Comments/thoughts?
2) Do you agree that the MPG will stay significantly higher with diesel compared to gas while towing??
3) Can you share what sort of MPG you get both towing and not with your gas and diesel 2500 or 250 trucks? The EPA doesn't rate the bigger vehicles and I want information!
THANK YOU for your help and guidance. Forgive me for a newbie question. You don't have to fret about being gentle in your answers - I'm fine with blunt. I just need advice regarding if we should change our order!
I suspect if we call tomorrow or Tuesday and revise our order it'll be possible still. I hate to not change it for fear of making folks irritated if it's the right thing to do. If it's a wash, then keeping it as is, is easiest and we'll have our TV before the Classic arrives.
-Linda

_________________________

First smell. No it doesn't smell in the cab. If you fuel up at truck islands their nozzles are larger than at auto islands, but they still fit in the Duramax fuel hole. The fuel may splash back if you try and fill it to the brim because diesel does foam somewhat. If the person filling the tank gets diesel on their hands that smell will come into the cab just as gasoline smell will if you get it on you.

Second, milage. Gas engines don't have as much torque so often they have lower differential gears. They often need higher than regular to gain most benefit, so price differential between a gallon of gas and a gallon of diesel disappears. Diesel and gas engines both have a mpg drop when hooked up, but you would love diesel. My wife is very sensitive to smells and she complained more about gasoline smells, than diesel.

Third, my 2016 2500HD Crewcab regular box 4WD Duramax with a Leer Topper gets 20-21 mpg highway unhooked at 70-75 mph. Hook up my 29' 1990 Excella weighing 7500 lbs full weight, and go down mildly hilly freeway at 65 and the milage is 14 mpg. Flat freeway 14.5 mpg. WV tollway mts 13-13.5 mpg. Speed up to 65-75 and milage is 19-20 mpg on gentle hills, flat freeway 19.5, WV tollway mts at 65-75 and milage drops to 12-13 mpg.

I don't know exactly what my Duramax weighs but as a 2016 it probably weighs very close to the two 2500HD GM vehicles you are considering. Your trailer may weigh close to mine fully loaded ready to go down the road. We did upgrade our axles, rims and tires from the stock ones, so we are now at our max weight.

If you can afford the extra for the diesel, do it, you won't be sorry.
+dcasr

[tjdonahoe]

My 07 dodge with 6.7 Cummings was 12.5 coast to coast, my new one will get better mileage ? Looking for 13-14 mpg while pullin the 31' classic...no comparison to a gas engine.....

[pappy19]

When you add up the extra cost of the diesel engine, usually around $8,000 more, extra maintenance costs for oil and fuel filters around $200 per change, urea tank refills, and added fuel costs, a gas engine is way ahead even with the 3-4 mpg diesel advantage towing difference. While the exhaust smell is much less than the old diesel engines, the diesel fuel smell itself is still the same and it gets on your hands. Your wife won't like the new perfume. The bottom line is that every person on this forum that has a diesel truck, WANTED A DIESEL TRUCK, but did not NEED a diesel truck to haul around their Airstream.

[Rgentum]

So far this summer & fall, I've put 15K miles on my Ram 2500 diesel towing an AS 27. At 60-65 mph on the flat, I get 22 mpg without the trailer and 14 mpg with the trailer. As more mountains occur, the towing mpg drops to 13 & then to 12, which is the worst I've ever gotten. To me, the feeling of being safe & in control of close to 50 ft of 15K lbs of rig is more important than out of pocket cost. The combination of the diesel's torque for raw pulling power & cruise control plus its exhaust brake for keeping my foot off its pedals while maintaining constant speed goes to make the towing close to effortless. My sweetie is much more sensitive than I to smells & of feeling anxious while riding, & she feels comfortable with the diesel/AS combination. Bottom line: the 2500 diesel/AS pair works for us. If it ain't broke, I don't intend to fix it.

[jonnie3]

I tow a 2015 FC 25FB with a 2016 Ram 2500 6.4 Hemi. I chose the gas engine over the diesel mainly because of payload limitations with the diesel. As I recall the difference between the diesel and gas engine trucks was about 1000 lbs in payload. I do use my truck as a daily driver. Just returned from a trip from Albuquerque to Anaheim averaging 11.2 mpg. I love my truck!

[Moflash]

For larger Airstreams the diesel is wonderful for towing.Mountain passes do not even phase them.The ability to merge into freeways and interstates at the traffic flow rate is as easy as a passenger vehicle with no strain.Cost of ownership is about the same as the diesel engine has a high resale value so you get back the majority of your initial investment difference.Preowned diesels are in high demand.Maintenance items a little higher but not excessive.
1.They do not smell
2.Fuel economy will drop when you are pulling a trailer.If you are buying a diesel to save fuel don't bother.
3.A 1/2 ton diesel is a poor choice for a larger Airstream.Not enough payload capacity.

We pull a 28ft International and started with a new F150 max tow and soon found out it was not for us.Traded for a new 2012 F350 6.7 turbo diesel and wow what a difference.Drove it 39k miles and traded for a new 2015 F350 6.7 turbo diesel.When it comes time to trade again it will be a 2018 F350 turbo diesel.Traveling with this rig is like driving a luxury car the ride is smooth and very quiet.You never have worry about how much things weigh when preparing for the next adventure.It takes the edge off just knowing that you have a capable vehicle designed for this purpose.

[IanPoulin]

I would refer you to my post (#4) in the F150 vs F250 thread where I give my impressions towing my International Serenity 28W with each: (spoiler; towing ability and milage with deisel for me are better)

http://www.airforums.com/forums/f463...50-158074.html

[roadwarriors]

Jim and Linda & anyone else who can help: We too will be getting our 2017 sometime in early 2017 and we are in the process of deciding on a TV. We are also looking at the Silverado and are trying to decide between the 1500 with tow package or the 2500. Please let me know why you chose the 2500? We looked at the towing capacity for the 1500 and it can tow up to 12000 lbs. We figure the trailer fully loaded and with whatever we decide to put in the truck will come under that limit. Your suggestions and advice will help as this is more difficult decision then which AS to order. I welcome anyone's comments on this issue. Many thanks. Kathy