Diesel vs gas......................

[blt2ski]

OK folks, there have been a few to many diesel vs gas threads that have shall we say gone to "Hell and a hand basket"! So if all of you would put in you BEST, no flaming reasons for going gas vs diesel, pro and con, I will either leave your thread, or copy and paste pertinant info to the 4 posts of pro and con of diesel or gas. This can include the GM 8.1 vs Dmax or Ford V-8/10 vs PSD etc too.

Be real and honest in you answers, not hear say, flaming etc PLEASE!

If posts are good ones, I will leave, if inflamatory or trolling in nature, they will be deleted! I will get this stick'd to the top for future parusing for those that need this type of info.

Added 6-23-04

We are getting closer to answers I am looking for etc.

Stuff like Ken's - T-Bone posts are good. There are a few others of you that have not posted, some with a 9 point question and answer type to figure out how you went with one or the other. If you are one of those, PLEASE repost in this thread. I may have to look up whom has done this and PM you, but if you think this is you, you now know what to do.

Also, for those of you with $ per gallon for either fuel right now, I would prefer to see a post with ...."in my area, diesel is typically .10 less than unleaded" then explain your numbers. As currently in the Seattle area, diesel and unleaded are any where from 2.05 -2.30 per gallon, with mid test .10 more and premium about .20 more, with equal high low splits. Two weeks ago those prices were upwards of .30 -.40 per gallon more. people were posting $ per gallon that were for me. "I wish" If someone is reading your post a year from now, they may want to know where your paying 1.65, when the price of fuel is over $3 per gallon. Let's keep prices out of it if possible.

Bert and tin tipi, got into a good discusion on the pros and cons of RPM's, drive train etc. I would prefer to NOT see the quote of the other in responding threads, maybe just write a quick wording of re tranny gearing, instead of the whole 40 words or so in that paragragh, so the repsonse is shorter if possible quicker and easier to read etc.

I have deleted some 15+/- posts, that were off topic etc. Please note, I am trying to keep this at the top, as the ONLY gas/diesel thread in this area. So if one is trying to decide, we do not have to go thru this BS any more. As such, I will be deleting ANY future posts close to resembling this type of topic. I may have to change "this" title to a better one, if one has a better sounding title, to be more positive, better claification, let me know here, or in a PM/e-mail, what ever you feel most comfortible with.

Again thank you for all of you that are keeping responses positive, etc.

Also we could use a few more positive reasons to go gas, as many can see I have both gas and diesel, both have a place! Both have positive reasons to buy that fuel, lets keep the threads etc to that purpose only!

Marty

[stephen_haley]

if you know your rig, you can calculate a safe amount of fuel to hold in your tanks for the trip. this goes for going and coming.
i'd leave a small bit of safety in it, something like 10% over. if you have 2 tanks split up the weight.
if you are not going to use it for more than 2 or 3 months i'd suggest taking it out every month for a short 2 hour run down the highway. the time spent is well worth it for your diesel.

stephen
soon to own my next RV

[Bunk]

What is the life of diesel? How long should it sit in a tank before being used? The reason I ask is I am thinking about buying a big truck with 200 gal. tank and would only use it about 5000 miles a year. Bunk

[DavidPhillips]

You will never see an 18 wheeler with a gas engine.

If your going to keep a truck a long time and or use it for towing all of the time then I would consider getting a diesel.

If your not worried about initial cost then get a diesel no matter what.

Diesels make power at lower rpm making them last longer in general as well as being able to use lower axle ratios.

Better mpg due to the higher burn temp of diesel. More power per gallon.

Heavy boats or ships are other good examples.


Not all diesel engines are direct injection. The ones with an injection chamber will require a glow plug system to start when cold.

Direct injection should not need a glow plug but it depends on compression, which seems to be dropping in the newer diesel engines to help them run cooler so more fuel can be dumped into them.

[hone_eagle]

Arnie L wrote:
I recently traded in my 2500HD gas 6L for a 350 PSD. After towing my 10,500lb Jayco up mountains last summer and feeling sorry for the stress I put on the gas engine, I knew I needed a diesel. If we had to worry about saving a few dollars we wouldn't be RV'ers but stay home, sit on the porch, tightwads.
Go traveling. Life is too short to worry about a few cents.

Totally agree!!!

[Arnie_L]

I recently traded in my 2500HD gas 6L for a 350 PSD. After towing my 10,500lb Jayco up mountains last summer and feeling sorry for the stress I put on the gas engine, I knew I needed a diesel. If we had to worry about saving a few dollars we wouldn't be RV'ers but stay home, sit on the porch, tightwads.
Go traveling. Life is too short to worry about a few cents.

[hone_eagle]

Bert, fyi I read a road test in a detroit newspaper this summer on a Audi gasser with direct injection,I dont recall the model,but the reviewer said a little diesely on cold start but torquey for a gas engine.

[stephen_haley]

i'm a user, not a mechanic.

when i buy, it'll be a diesel for 3 reasons.

first there will always be diesel no matter what. the govt. won't let the transportation industry come to a halt, ever. it may slow down or get expensive, but the truck stops will forever be open to a large degree.

second, you just can't get the HP out of a gasser without trashing the enigne. bnand new 2006 ford and chevy engines are noted on all sales material i have seen as being able to go a maximum of 150,000 miles. during the last 50,000 miles i'd suspect the wear and tear to drop off lots of HP and service and maintenece becomes a nightmare.

third, i'm pulling a full size pick up. standard cab, long bed, empty. can't do it on a gasser without wearing the engine out on hills.
as as side bar;
can someone tell me if they have any idea as to how some older rigs, in excellent condition, with a DP, have only 60,000 or so miles over 10 or more years. i am looking into some Foretravels and they are all low mileage and in pristine condition. i know if a gasser is left idle for long it just begins to fall apart, leaks develop and so on. you need to use them on a regular basis.
is it not the same for a DP? even though it's gonna get 500,000 miles on a single engine, it seems 10 years with only 60,000 tells me it sat a lot.

what do you pro's think.

stephen
soon to be MHDP owner

[BertP]

hindle_az - Nice explaination of how a gasser works vs how a diesel works. There is work being done now on building a gasser that has direct injection just like a diesel. Apparently there have been some promising results, but there are no production engines yet. Since the fuel will be directly injected, they will be able to raise compression ratios much higher than they are now and get much better efficiency out of them. It will certainly be interesting to watch.

Jim - The reason that reliability dropped is because the typical gasser does not provide any piston cooling - it's not required. However, when you charge the intake, piston temps climb dramatically and if you don't do something about it, you will end up with burned pistons. Any engine that has a charged intake (gas or diesel) will experience increased piston temperatures. Usually, jets of oil are sprayed on the bottom of the pistons to cool them. My DMax has them but the 6l gasser I had did not. Also, you can't run stock head gaskets in an engine that is producing substantially more power than stock regardless of how that extra power is being generated. There are all kinds of after market head gaskets available that will withstand the increased power without failing.

Bert

[JIMNLIN]

hindle_ az
turbo a gas tow engine and the reliability goes out the window. Gas engines we use in our tow vehicles arn't specked for added boost either with a supercharger or turbo to last several hundred thousand miles while towing full time. We ran a few s/c and turboed 454/460 one ton trucks years back towing our race cars and heat from boost was our eternal problem when pulling long grades. Didn't take us long after blown head gaskets and burned pistons to stay stock. Much more to a turbo diesel engine lasting 200-400000 miles while towing than than the injection system differences.
Bring the boost up on a diesel, 20-30 lbs, at 2000+ rpm and pull 26000+ lbs all day long. Thats the typical life of a hotshoter workin' his turbo diesel. A gasser with any kind boost or not can't compete economicaly or mechanicaly. Apples to oranges.......JIM

[hindle_az]

On another note many posts back people were arguing more about the power and pulling up hills versus gas mileage. I don't remember the names but we were arguing over turboing the gas engines and how they could be just as effective as the Diesels. Then that got me thinking about why the commercial trucking industry uses Diesel's and why are all the Diesels from Ford, Dodge, Chevy turbod but not the gassers. So I started to research and thought I would post some info incase there were others like me that wondered the same things.

In a gas engine the air and fuel is mixed in the intake manifold prior to entering the combustion chamber. I'm sure most of us already new that. Here is where it gets interesting. When you compress oxygen it heats up. If you have fuel mixed in with that oxygen and you compress it enough it will ignite due to the oxygen heating up under compression. This is why people run injection systems and intercooler on turboed or supercharged gas engines. They want to run more boost to make more power but you have to cool the air/fuel mixture so you don't get preignition. Most of the hotrodders I know running more then 8 -12 pounds of boost are also running an intercooler or some type of injection system to cool down the air before it enters the combustion chamber.

What makes Diesel's unique from Gassers is that the air and fuel is not mixed together in the intake manifold. Only air enters the combustion chamber. The Direct fuel injection system is timed much like the spark on a gas engine is. The Diesel is injected directly into the combustion chamber at the right time. Since the Diesels run so much more compression then your typical gas engine the fuel ignites as soon as it's injected just like a spark plug ignites the air/fuel mixture in a gas engine. Since the fuel and air is seperated you can compress it much more without preignition problems. This is also how some of the new Diesel's start cold without glow plugs. The computer simply retards the injection timing so the air is getting compressed more then normal before injecting fuel. Since it's compressed more it's hotter then on normal starts and thus no glow plugs.

Sorry for the looong post but I found all this very interesting and thought I would share with everyone.

[hindle_az]

Ron O'Brien wrote:
well no doubt the diesel will get better fuel mileage -- however how come no one mentions the fact that to buy the diesel you will pay $6000.00 to $7000.00

your right if your buying new the diesel option usually costs more and may not make sense for somebody who tows once or twice a year and gets a new truck every 3-5 years

Ron O'Brien wrote:
also to maintain the diesel engine the costs are more,not to mention the smell and polution factor

I bought an 02 Duramax that had 50k on it. 23,000 thousand miles later the only thing I've done differently is fuel filter changes. You have to do them more often then on a gasser but the filters are not to much more expensive and on the Duramax it's not to difficult to do. 30 minute job. Everything else (engine oil, oil filter, tranny fluid/filter, brakes, belts, diff, etc...) is going to be there no matter what you drive and hasn't been anymore difficult or expensive then on a gasser.

As for the smell - they do smell more then a gasser that is for sure as for pollution I'm not an expert in that area so I can't really say more or less or worse, etc...

[hindle_az]

More and more I see people talking about the price per gallon for Diesel versus Gas and how Diesel's no longer have an advantage in the mileage department. I can't speak for every truck and every trailer out there but in my particular case Diesel still costs less. You have to look past the price per gallon and do the math.

I have a toy hauler that I take to motocross races in my area. I get 10.5 MPG. I have a friend with a gas truck that has a very simliar trailer in size and weight. He tells me he gets around 7. The cheap unleaded in my area is around 2.20 a gallon while Diesel can be had for around 2.50. If I drive 400 miles round trip with my trailer it costs me around 95 dollars. While my friends total costs is around 126 dollars. So while he is paying less per gallon he is using more gallons for the same trip and in the end pays more then me. We both have GMC's. I have the duramax and he has the 6.x gas version. Displacement wise the engines are very close as the Duramax is 6.x liters as well. I'm sure the 8.1 gas option would provide alot more pulling power but I don't see it getting many more MPG then the smaller 6 liter version.

Like I said this is just my particular situation but until Diesel gets to around 1 dollar more then unleaded it will still pay to run the Diesel and even then it's a break even situation and you still have other advantages to draw from if you tow often. I realize there are those that don't tow often or plan to keep the truck to pay off the extra cost of the Diesel option (if your buying new) and like I said this is just my situation but my main point is you can't just look at the simple price per gallon. It's deeper then that.

[stephen_haley]

Lynn Rupper wrote:
Don't forget to factor in the gas engine will last about 150/200k miles and the diesel engine will double that. All you have to worry about is will the truck components and body last that long.

new manufacturers of MH state in their printed material that 150,000 miles is the maximum expected mileage on a gas engine.

since the last 3rd will provide less pull and efficiency, i believe it's just smart to buy diesel if you can afford it.

stephen

[Paul_Clancy]

Ron O'Brien wrote:
well no doubt the diesel will get better fuel mileage -- however how come no one mentions the fact that to buy the diesel you will pay $6000.00 to $7000.00 more than a gas engine and I have read that it will take 80000 miles to recover this money-- also to maintain the diesel engine the costs are more,not to mention the smell and polution factor-- not the truck to just go downtown for the mail-- but a truck to be driven long and hard 12 months of the year.Not the average joe------

You get the extra cost of the engine back on trade/resale. Check used prices. I don't agree with the extra maintnence claim. So far I've spent no more than my gas truck. Lots of diesels at the mall, parked downtown etc....just as good a commuter as a gas truck. Low sulpher fuel and quiet diesel tech makes your points only applicable to old out of tune trucks. I'm not suggesting everyone buy a diesel, just that I cant imagine going back to gas after feeling the pulling power of diesel.

[joheath]

If your towing anything that weighs more than your tow vehicle, a diesel is the only way to go. Gas is somewhat easier and cheaper to work on, but if you need towing power (torque) the extra expense of a diesel is well worth it.