Forum Discussion
219 Replies
- wilber1ExplorerWhen it comes to power, the biggest difference between the 8.1 and the diesel is the turbocharger, not the fact one is diesel and the other gas. Take the turbocharger off a DMAX, PS or Cummins and the 8.1 will eat their lunch. A 6.0 will eat their lunch. Turbo diesels are great for towing but you couldn't give me a normally aspirated diesel.
- cdlaineExplorerSirs,
Am not as sophisticated in the understanding of all the parameters
listed in this discussion (as most). I run (original owner) the vehicle posted in my signature block.
My current tow configuration (at CAT wt. listed) delivers 7-8 mpg
average under load. I tow at 55 mph with tow haul and cruise control.
My "average" RPM level is 2300-2500... on 6% upgrade 3500-3800. Most times maintaining cruise control speeds. I probably "get there" 45 min. - 1 hr. later (maybe a little longer) then most (that is the real import of this discussion isn't it ???). I have never pushed my tow vehicle to "max" but at my current use seems to have performance increase left available... My transmission temp gauge consistently stays 200 - 230.I have always been able to maintain forward momentum even on the steepest upgrades (ie have never rolled backward).
I religiously maintain my vehicle... and recently had the Allison serviced by a service center, not a dealership.... no metallic shavings noted.
10 years of ownership of my tow vehicle has been pleasant ... I hope
I get another 10 . Current unleaded mid-grade (Phoenix metroplex)...
$3.40 - $3.63 , Diesel... $ 3.47 - 3.64 (per Gas Buddy app).
I have made a point to remind myself that I'm pulling a house over mountain grades to get to someplace cool so try not to fret over MPG.... is what it is.
Would I do it again ? Yes.
Charles
edit- my only mod ... K & N filter . Only chip I use is edible. - rhagfoExplorer III
Taco wrote:
Yes they have the same pulling capability. They will go the same speed over the same terrain. The gas will do it at a higher rpm and consume more fuel.
I seriously don't buy it that a diesel engine is any longer lasting or more reliable for the engines they put in a light duty truck. The engines they put in light duty pickups are not the same they put in class 8 trucks, container ships, locomotives, bulldozers, or any other commercial application. Just because the engine in a class 8 truck lasts a certain number of miles doesn't mean because it uses the same type of fuel, the light duty pickup engine will do the same.
The diesel heads of this site regularly do the folks who come on here looking for advice a disservice. They tell them they need a diesel, so the person goes and spends 9k more for the diesel being assured they need it and it will last forever. When it will last no better and a gas engine will do the job also.
Just a few minutes ago a diesel owner made a post that his diesel truck only lasted 100k and he was led to believe they lasted a long time. Could have probably saved himself enough cash on that diesel purchase that even if he got a gas engine and even if it failed he could have bought a new engine.
100K diesel death must have been a Ford 6.0. That is not the norm I still pull 11,000# 5er at 260,000 miles. I expect another 260,000out of it.
As to the cost of diesel, gas at $3.50 and diesel $4.00 gas 8 mpg and diesel 12 mpg. That places the diesel at 15% more than gas, but getting 50% better mileage! I will stick with the diesel, most gassers that slam diesels have never towed with one if they did they would understand why we like our diesels. - TacoExplorerYes they have the same pulling capability. They will go the same speed over the same terrain. The gas will do it at a higher rpm and consume more fuel.
I seriously don't buy it that a diesel engine is any longer lasting or more reliable for the engines they put in a light duty truck. The engines they put in light duty pickups are not the same they put in class 8 trucks, container ships, locomotives, bulldozers, or any other commercial application. Just because the engine in a class 8 truck lasts a certain number of miles doesn't mean because it uses the same type of fuel, the light duty pickup engine will do the same.
The diesel heads of this site regularly do the folks who come on here looking for advice a disservice. They tell them they need a diesel, so the person goes and spends 9k more for the diesel being assured they need it and it will last forever. When it will last no better and a gas engine will do the job also.
Just a few minutes ago a diesel owner made a post that his diesel truck only lasted 100k and he was led to believe they lasted a long time. Could have probably saved himself enough cash on that diesel purchase that even if he got a gas engine and even if it failed he could have bought a new engine. - bmanningExplorer
wilber1 wrote:
rhagfo wrote:
wilber1 wrote:
If you want to compare diesels with gassers, comparing normally aspirated gassers with turbocharged diesels is a waste of time. Stick some sort of blower on a gas engine and fuel consumption aside, the differences become much less apparent.
Well a turbo charged diesel can still get about 12 mpg towing 11,000# at 60 to 65 mph. Try that with a tubroed gas engine more like 8 mpg if lucky.
I like my diesel as good mileage, long engine live, low maintenance, and lots of power.
That's why I said, fuel consumption aside.
Things have leveled out a bit but when diesel was a solid $0.50 or so more than 87oct the difference between 12mpg diesel & 8mpg on 87 would not be that significant.
Side note, glad to see that diesel fuel prices have dropped a bit. Fuel price was a big reason I sold my 7.3L (back in 08 when diesel hit about $4.75/gal) - transamz9Explorer
bimbert84 wrote:
transamz9 wrote:
It takes torque to keep the vehicle speed up. RPMs measure engine speed, which can easily be increased by downshifting in the transmission.I don't care how you look at it , it takes torque to keep the RPM's up.
transamz9 wrote:
Of course it can. The whole point of a transmission is the put engine RPMs in the optimal range at whatever speed the vehicle is moving. It's just that with a gas engine, those RPMs will (usually) be higher than with a diesel.A gas motor can't make the torque at highway speeds to keep the RPM's up when put under a load without going out of it's optimum RPM range.
-- Rob
The RPM's I'm referring to is at the rear wheels (on the ground where it counts). This is what I've been talking about. These motors are TUNED to run their best at their intended use RPM's. That RPM in vehicles is 1500-2000 give or take. Marine engines (gas) 5000-6000 in must cases. Lawn mowers is 3500-3800. So on and so on. My Corvette has no problem running around in the 1500-2000 range. Even on take off it shifts at or before 2000 rpm's.
It would be different if they would build truck engines like they use to. Now they just use the same engine and tune it differently. The old 454 such use to just be able to lug right on up a hill. - wilber1ExplorerAn un boosted engine needs to rev to make power, doesn't make any difference whether it is diesel or gas. It's all about how much air the engine can pump.
- bimbert84Explorer
transamz9 wrote:
It takes torque to keep the vehicle speed up. RPMs measure engine speed, which can easily be increased by downshifting in the transmission.I don't care how you look at it , it takes torque to keep the RPM's up.
transamz9 wrote:
Of course it can. The whole point of a transmission is the put engine RPMs in the optimal range at whatever speed the vehicle is moving. It's just that with a gas engine, those RPMs will (usually) be higher than with a diesel.A gas motor can't make the torque at highway speeds to keep the RPM's up when put under a load without going out of it's optimum RPM range.
-- Rob - wnjjExplorer II
transamz9 wrote:
I don't care how you look at it , it takes torque to keep the RPM's up. A gas motor can't make the torque at highway speeds to keep the RPM's up when put under a load without going out of it's optimum RPM range.
Exactly right. If you let the gas engine run where it makes its power it will pull just fine. People seem to insist on letting it shift back into "mileage mode" when hauling a load and then complain when "it keeps shifting down and back up." The diesels' good mileage RPM is really close to its power generating RPM because it simply doesn't have as much of a range of RPM. More fuel is added when power is needed and less when not. The gas engine rev's to make power.
Overdrive is great for a low rev'ing diesel or unloaded gas engine. It doesn't work so well when trying to keep a gas engine making its best power. - wilber1Explorer
rhagfo wrote:
wilber1 wrote:
If you want to compare diesels with gassers, comparing normally aspirated gassers with turbocharged diesels is a waste of time. Stick some sort of blower on a gas engine and fuel consumption aside, the differences become much less apparent.
Well a turbo charged diesel can still get about 12 mpg towing 11,000# at 60 to 65 mph. Try that with a tubroed gas engine more like 8 mpg if lucky.
I like my diesel as good mileage, long engine live, low maintenance, and lots of power.
That's why I said, fuel consumption aside.
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