2020 Silverado Diesel 3.0 EPA Rated...

[redpoint5]

Yeah, Oregon/Washington fuel prices are always more than mountain/south prices. CA is even higher yet.

Lots of stations in MT have regular at 85 octane though, so that might help prices a bit.

[Ecky]

I’d love to see ones of these get a full eco treatment - chop the top, lower it, underbody paneling, aero bed cover, skirts, slightly narrower and LRR tires, weight reduction, gearing compensation for reduced load.

[Hersbird]

Originally Posted by redpoint5

Yeah, Oregon/Washington fuel prices are always more than mountain/south prices. CA is even higher yet.

Lots of stations in MT have regular at 85 octane though, so that might help prices a bit.

I'm not positive how it works but I think that 85 octane is the same exact gas they sell at 87 in Washington and Oregon it just gets labeled the lower rating because of the average elevation

[redpoint5]

Originally Posted by Hersbird

I'm not positive how it works but I think that 85 octane is the same exact gas they sell at 87 in Washington and Oregon it just gets labeled the lower rating because of the average elevation

That was the opposite of my understanding, that MT 85 is 85 PON, but it has similar resistance to burning at elevation as 87 PON at sea level. Lower atmospheric pressure > lower air density > lower compression heat > lower risk of detonation.

We all observe that the higher the octane rating, the higher the price of fuel, so my assumption is that 85 PON is cheaper to produce.

I run 85 PON when I'm in MT, but then I fill up with "premium" as I head out, prior to descending back to sea level.

[Hersbird]

Originally Posted by redpoint5

That was the opposite of my understanding, that MT 85 is 85 PON, but it has similar resistance to burning at elevation as 87 PON at sea level. Lower atmospheric pressure > lower air density > lower compression heat > lower risk of detonation.

We all observe that the higher the octane rating, the higher the price of fuel, so my assumption is that 85 PON is cheaper to produce.

I run 85 PON when I'm in MT, but then I fill up with "premium" as I head out, prior to descending back to sea level.

I was wrong, I went and looked it up, it is different. It's just most cars can get away with it at altitude. I know I've always ran it in all the cars I have ever had and never had any problems. I bet you could actually get away with it in most cars at any altitude, so I'm glad I at least get a choice. I read in Colorado still 80% choose 85, and about 10% chose 87 and 10% choose 91. If you just are driving normal in a normal car saving $.10-15/gallon is great especially at these low prices. When it goes to $4/gal then it still seems to be at same $.10/gal extra for 87 but it doesn't seem like that much extra.

[redpoint5]

Modern cars will mostly be ok running 85 at sea level because they can retard the timing to protect the engine. My Acura might actually become damaged over time if it isn't able to retard the timing enough to prevent knock. The manual states that the engine is designed for 91 octane, and that 87 is the minimum to prevent engine damage.

In OR, we have 87, 89, and 92. BTW, mid grades are always a blend of regular and premium (ever see a fuel truck with 3 tanks?). 89 is 60% regular and 40% premium. Anyhow, I mostly run 87 in my Acura, but lately have been alternating filling up at mid-tank with 87 and 92 to average out somewhere around what it's designed for.

I can "feel" the difference in normal driving between regular and premium in my Acura. This difference is confirmed in more advanced timing on premium, and less advanced timing on regular.

[slowmover]

Originally Posted by Hersbird

The other good thing about this Silverado is the 6.2 gas and 3.0 diesel are both priced the same. About $2500 more than the 5.3 v8 so it should pay for itself much sooner than a $5-6k Cummins upgrade. The good thing on the Cummins you can usually get back almost all that at resale compared to a gas Ram.

The 6.2L 400HP engine can crack 20-mpg at 60-mph.

The baby diesel let’s say will do 30 under the same conditions.

That’s a difference of 85-gallons in 5k miles.

If gasoline is $2.50 and diesel $3.00, it’s not much of a savings at $125.

15k annual applicable miles, and it’s $3,750 over ten years.

No IRS depreciation, etc, and needing VERY high annual miles it’s just another vehicle badly spec’d for private use.

.

[cRiPpLe_rOoStEr]

I'd like to see what it could get with an engine more similar to the Cummins ISF3.8 and that 10-speed transmission, considering my previous experience with a Brazilian F-250 4WD regular-cab which was factory-fitted with a Cummins ISB3.9 and a 5-speed manual. With a lead foot it could get around 20MPG, while a more conscious driving would get it around 30MPG.

Originally Posted by Hersbird

The I6 was rare into the 70s and 80s in trucks (pretty common in GM cars) and they may have only been available in what they may not have considered "light duty" trucks (even though according to DOT even a 2020 Duramax 2500 Silverado HD is "light duty"). Still up until the mid 50s it was the only motor available in a Chevy pickup. Agreed a bad claim.

Last time an inline-6 gasser had been available for a GM truck was before the production of the GMT400 shifted from Argentina to Brazil between late-'99 and 2000. There was also a turbodiesel inline-6 sourced from MWM which soldiered on until the GMT400 was phased out in Brazil in late 2001.

Originally Posted by Hersbird

A lot of it may have to do with the 2.8 gets a 6 speed and the 3.0 gets a 10 speed.

I'm sure the 10-speed transmission might've held an important role for an old Bolivian to tell me his late-model F-150 Lariat with the 3.5 Ecoboost was somewhat a fuel-saver.

I also suppose more smaller cylinders may be more efficient at complete diesel burn than fewer larger cylinders even though you have 2 extra sets of rings and a few more bearings.

Compression ratio, injection pressure and the fuel spray have more to do with a complete burn than the cylinder bore.

[Hersbird]

Originally Posted by slowmover

The 6.2L 400HP engine can crack 20-mpg at 60-mph.

The baby diesel let’s say will do 30 under the same conditions.

That’s a difference of 85-gallons in 5k miles.

If gasoline is $2.50 and diesel $3.00, it’s not much of a savings at $125.

15k annual applicable miles, and it’s $3,750 over ten years.

No IRS depreciation, etc, and needing VERY high annual miles it’s just another vehicle badly spec’d for private use.

.

Except the baby diesel can crack 43 mpg at 60 mph, it will certainly beat the 33 mpg EPA rating. Also currently even in Montana where diesel prices are usually well over unleaded (one big reason I sold the Cummins) now gas and Diesel are within 3 cents of each other.
So say 35 mpg vs 20 and 10c more for diesel. That is a $860/yr savings for the same initial price based on average miles driven.
They both make the same 460ft-lbs of torque as well.
To me if buying a new GM pickup the choice would be a no brainer.

[slowmover]

1). Expect that diesel pricing will continue to reflect the 1/3-more energetic content of that fuel. THEN make your calculations.

2). Then it comes to use. “Solo, empty”, ISN'T a valid category.

Then IRS applicability.

Against a gasoline big block of 20-yes ago or more, yeah, it’s great. Against today’s gassers, barely.

We built this country without pickups. It’s “need” now is still more “want”. Desire.

The higher risk of accidents (and type) ALWAYS mitigates against pickups. (“Skill” is a laughable counter).