Diesel vs Gasoline

85_Ranger4x4

Well-known member
No, not really. The numbers are the numbers. Feel free to make your case for how they're not accurate



If you go back and re-read, the extra 30 gallons referred to WEIGHT.... diesel drivetrains are heavier, diesel fuel is heavier per gallon. Adding 30 gallons of gasoline only brought the gasser up to weight parity with the diesel.

Yes, volume of fuel is another consideration. Of course you glossed over that with the extra 30 gallons on board (same weight for weight) you'd also have an additional **325 miles of range**

Don't need the range, and don't want to take up the volume?

25 gals x 20 mpg Diesel = 500 miles of range.
33 gallons x 15 mpg Gasoline = 500 miles of range.


Therefore, to have range parity, a gasoline vehicle would have to carry an additional 8 gallons. The gasser would still weigh a lot less than the diesel, as 33 gallons of gasoline weighs 218 lbs versus 25 gallons of diesel at 180 lbs... a 38 lb addition. The diesel engine option alone offsets this 38 lbs by a large amount. My guess is that most guys on this forum could lose 38 lbs... yet they don't, instead blaming what they carry

To play devils advocate you can sometimes get heavier duty suspensions with the diesel over a gas which would offset the weight of the engine from a legal standpoint. Not sure on the newer trans (older trucks, at least F-series were similar gas/diesel) but the rest of the driveline is generally about the same.

Still going to be more nose heavy though.
 

lucilius

Active member
Dual tanks used to be pretty common from the factory for gassers. It was a factory option on my truck.

It is hard to find tanks because JY's just stab tanks to drain them but I would like to add a tank to mine.



Certain years do require cab removal to work on the engine, mainly the 6.4L. Before they started getting crusty you could just lift the cab off the frame like a bodylift height (not requiring messing hoses and electrical) to like pull the turbo but with age it is easier to go all the way now.
No. To clarify, you will of course find shops and mechanics who will tell you that a 6.4 needs the cab removed, but this is a preference (or capability/experience limitation), not a requirement. Any maintenance/replacement task on an 08-10 super duty with the 6.4 can be accomplished without cab removal, up to and including a full motor replacement...though I agree it will be easier and more cost effective in most cases to remove the cab.
 

nickw

Adventurer
For the same fuel capacity, a diesel engine (of comparable torque output to the gasoline alternative) will get you farther.

While Id agree with the statement, your now comparing two rigs that have very different performance baselines and I can't think of any two similar class modern vehicles where this comparison can be done, aka same torque, drastically different HP, it's an apples to oranges comparison. You could probably look at one of the old cummins 5.9's with 160 hp and 400 tq relative to something like the modern Ford 6.2 which is close tq wise but has ~2.5x the power. I'm sure the Cummins would get much better MPG, but would have significantly less performance at speeds higher than a crawl...
 

Dalko43

Explorer
No, not really. The numbers are the numbers. Feel free to make your case for how they're not accurate

They aren't....that's my point.

If you go back and re-read, the extra 30 gallons referred to WEIGHT.... diesel drivetrains are heavier, diesel fuel is heavier per gallon. Adding 30 gallons of gasoline only brought the gasser up to weight parity with the diesel.

Yes, volume of fuel is another consideration. Of course you glossed over that with the extra 30 gallons on board (same weight for weight) you'd also have an additional **325 miles of range**

Don't need the range, and don't want to take up the volume?

25 gals x 20 mpg Diesel = 500 miles of range.
33 gallons x 15 mpg Gasoline = 500 miles of range.


Therefore, to have range parity, a gasoline vehicle would have to carry an additional 8 gallons. The gasser would still weigh a lot less than the diesel, as 33 gallons of gasoline weighs 218 lbs versus 25 gallons of diesel at 180 lbs... a 38 lb addition. The diesel engine option alone offsets this 38 lbs by a large amount. My guess is that most guys on this forum could lose 38 lbs... yet they don't, instead blaming what they carry

You're talking very much in the hypothetical here...the real world truck configurations don't really reflect your theory.

A) In most cases, its the truck chassis/suspensions are the limiting factors, not the engine and fuel weight. Meaning that going from a Ram 2500 gasoline to a Ram 2500 diesel, the loss in payload capacity DOES NOT equal the weight difference between the 2 drivetrain configurations. The payload loss is usually much less, in some cases negligible.

B) You're focused on the weight. I'm saying for an equal amount of capacity (volume) diesel gets you further. In the standard fuel capacity for midsized trucks (about 19-21 gallons) a 2.8l duramax is going to get you much further versus a NA v6 or even the Ranger's turbo inline 4 gasser. You can add some jerry cans to that midsized's bed to increase the range, regardless of it being gasoline or diesel...either way, diesel still has a range advantage.

C) Storing extra gasoline is much more complicated and riskier versus storing extra diesel...refer back to my point on combustion points. Also the reason gasoline auxiliary tanks are far less common than they are for diesel is because of emissions issues.

D) There must be a reason that every market outside of North America prefer diesels for their trucks...range/efficiency has a lot to do with that. You load up a gasoline 1/2 ton or 3/4 ton truck with all the extra fuel you talk about in your hypothetical scenario....you're no longer getting 15 mpg at that point. Gasoline engines really lose their efficiency when loaded up, or under high work loads. The rest of the world figured that out. The average Joe Schmoe in America or Canada who drives his or her pristine 1/2 ton to and from an office job doesn't really care about that range issue....he just cares about HP bragging rights and going fast from a stoplight.
 

Regcabguy

Oil eater.
No. To clarify, you will of course find shops and mechanics who will tell you that a 6.4 needs the cab removed, but this is a preference (or capability/experience limitation), not a requirement. Any maintenance/replacement task on an 08-10 super duty with the 6.4 can be accomplished without cab removal, up to and including a full motor replacement...though I agree it will be easier and more cost effective in most cases to remove the cab.
Looks like a lot of work. I couldn't imagine being a tech and having to do this.
 

Dalko43

Explorer
That is inaccurate. Ford diesels do not require cab removal for maintenance....it just makes things a lot easier i.e. less expensive and time consuming.

Not really less expensive....at least compared to other brands where cab removal isn't required.
 

85_Ranger4x4

Well-known member
C) Storing extra gasoline is much more complicated and riskier versus storing extra diesel...refer back to my point on combustion points. Also the reason gasoline auxiliary tanks are far less common than they are for diesel is because of emissions issues.

D) There must be a reason that every market outside of North America prefer diesels for their trucks...range/efficiency has a lot to do with that. You load up a gasoline 1/2 ton or 3/4 ton truck with all the extra fuel you talk about in your hypothetical scenario....you're no longer getting 15 mpg at that point. Gasoline engines really lose their efficiency when loaded up, or under high work loads. The rest of the world figured that out. The average Joe Schmoe in America or Canada who drives his or her pristine 1/2 ton to and from an office job doesn't really care about that range issue....he just cares about HP bragging rights and going fast from a stoplight.

When you can get a 20mpg+ F-150 with a 36gal fuel tank (and roughly 700+mi range) off the showroom floor... who cares about extra fuel tanks? Especially in a country you have to really try to get more than 100 miles from a gas station.

The rest of the world doesn't really care about diesel emissions and in addition to the typical diesel drama (glow plugs, injectors, gelling...) the rube goldberg crap they have to stick on a diesel in the US for emissions is what kills my desire to be involved with one.

Not really less expensive....at least compared to other brands where cab removal isn't required.

The flipside is with the cab gone you are basically working on a bare engine which will make things easier.
 

nickw

Adventurer
D) There must be a reason that every market outside of North America prefer diesels for their trucks...range/efficiency has a lot to do with that. You load up a gasoline 1/2 ton or 3/4 ton truck with all the extra fuel you talk about in your hypothetical scenario....you're no longer getting 15 mpg at that point. Gasoline engines really lose their efficiency when loaded up, or under high work loads. The rest of the world figured that out. The average Joe Schmoe in America or Canada who drives his or her pristine 1/2 ton to and from an office job doesn't really care about that range issue....he just cares about HP bragging rights and going fast from a stoplight.

I think a couple main reasons overseas, fuel prices have promoted fuel efficiency over performance and they don't or didn't have the requirements for higher powered vehicles due to speed limitations. I work with a bunch of folks from the UK, Scotland, Ireland, etc. and they all grew up driving N/A 1.X diesel cars. The lusted after the turbo gas versions. Same can be said for some of the older diesel trucks, N/A hiluxes and other midsize vehicles back in the day wouldn't have the power keep people happy with the higher speeds in the US. Larger displacement V8's worked well and we started to get the infrastructure to support it...just as overseas they had the infrastructure to support diesel so continued the development of them. Has very little to do with "range" as large tanks could easily be fitted or designed if that was required on gas engines, although folks naturally gravitated towards diesels because of it for expo use.

It really wasn't until the diesels started getting turbo-charged in light duty trucks that they really started to take off here...which was what, early 90's? Not that long ago. The old non-turbo GM 6.2s, Cummins 5.9's and the OLD SCHOOL Nissan 2.8 (I think it was) in the Scout.....were workable but hardly palatable to the majority of people when you could step up to a gas engine and get 2x+ the power.

We have this nostalgia for old diesels, fact was, back in the day, very few people wanted them. In speaking with some of the old timers, they all wanted the big gas V8's and seemed to get around and explore just fine without any of your worries.

In the far northern climates the Russian GAZ trucks were (and may still be) gas powered, which have seen more action and expo use than 99% of anything else out there. They may have to carry a 55-gal drum of extra fuel, sure, but certainly a workable solution....
 

billiebob

Well-known member
And broke down 5x more often. And burned 50% more fuel. Oh, and needed adjusted when changing altitude, and needed 3x more routine maintenance, and still needed a valve job every 60k.
And still costs less over its life time than any modern diesel. Definitely more reliable than any modern diesel.
And built to make all that maintenance easy and economical.
I'm sold, my next vehicle WILL have a carburetor.
 

85_Ranger4x4

Well-known member
And broke down 5x more often. And burned 50% more fuel. Oh, and needed adjusted when changing altitude, and needed 3x more routine maintenance, and still needed a valve job every 60k.

This day in age if you have an engine that looks like that and have any of those issues it is because you don't want to deal with them them.

My 302 (introduced in 1968, mine is an '87 so it has 20 years of factory upgrades built into it) is pretty reliable, gets the same high teens as most modern midsizes, I want to get a FITech kit for elevation but my 4bbl has treated me well. The only maintenance is oil changes, spark plugs and fuel filters like anything else. Hardened valve seats (and factory roller cam) ******.

I could run factory multiport EFI with distributorless ignition if I wanted but I like the factory period look I have going (inspired by mid 80's 5.8HO trucks and Mustang GT's)

 
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luthj

Engineer In Residence
Yeah, on ever single metric, modern engines are better. Initial reliability, longer term reliability, fuel economy, power, driveability, etc. I have had numerous vehicles go 200k+ miles with no engine maintenance or repairs except filters, oil, etc.
 

billiebob

Well-known member
Yeah, on ever single metric, modern engines are better. Initial reliability, longer term reliability, fuel economy, power, driveability, etc. I have had numerous vehicles go 200k+ miles with no engine maintenance or repairs except filters, oil, etc.
My '87 YJ had the 258 carbureted straight six, a design from the 1960s. I sold it with 350K miles on it still reliable, still running, getting better gas mileage than my '05 Rubi. I could not say the Rubi 4.0L is better or worse than that 4.2L, they are just different. But at -40 that carbureted 4.2L would start every morning. The EFI 4.0L would flood unless it was plugged in.

I specifically sold my Toyota Four Runner and went shopping far a carbureted engine for that reason. In arctic temperatures carbs are more reliable.
 

85_Ranger4x4

Well-known member
My '87 YJ had the 258 carbureted straight six, a design from the 1960s. I sold it with 350K miles on it still reliable, still running, getting better gas mileage than my '05 Rubi. I could not say the Rubi 4.0L is better or worse than that 4.2L, they are just different. But at -40 that carbureted 4.2L would start every morning. The EFI 4.0L would flood unless it was plugged in.

I specifically sold my Toyota Four Runner and went shopping far a carbureted engine for that reason. In arctic temperatures carbs are more reliable.

I don't know as I have ever flooded an EFI engine before...

Below 10*F my F-150's PS pump groans for awhile but it never misses a beat starting, we have been down to -20*F and it has been faultless.
 

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