Preferred gas engines for 1 ton pickups

[flusher]

The difference in a truck engine and the Hemi is that a truck engine will have a sharp torque rise and then a flat curve. The Hemi doesn't, it's a good car engine though. An example is the 8.1 as used in the 4500 and 5500 series GM trucks. From 2000 RPM to 4000 RPM the torque curve is just about flat. Same as what you see in a Diesel just that the Diesels drop off sharply in both HP and torque above a certain lower RPM point.
GM's curves can be found at http://eogld.ecomm.gm.com/images/mediumduty/techspecs/engine.pdf

FlaDon:
Thanks for the GMC power info. Great stuff.
I'll admit that I haven't been looking a GMC 1-tons lately. Maybe I should do a little homework on GM trucks, just to cover all the bases (F-series, Ram, GMC).

 

[ME83]

The GM 6.0L is a good truck engine, their downfall is before 2007 they only had a 4 spd auto. The newer 6.0L have more power, but people pick up 50-60 hp with an exhaust and tune.

The link is to a dyno sheet of a stock LQ4 (older 6.0L). Notice the torque curve, yet if you listen to people here the Hemi make more power all around than any other engine .

Vortec 6000 6.0L V-8 LQ4 Tech Article by BillaVista - Pirate4x4x.com

 

[Hematite]

ME83:

YES, that is what a TRUCK torque curve is supposed to look like!

 

[Diamondpilot]

The GM 6.0L is a good truck engine, their downfall is before 2007 they only had a 4 spd auto. The newer 6.0L have more power, but people pick up 50-60 hp with an exhaust and tune.

The link is to a dyno sheet of a stock LQ4 (older 6.0L). Notice the torque curve, yet if you listen to people here the Hemi make more power all around than any other engine .

Vortec 6000 6.0L V-8 LQ4 Tech Article by BillaVista - Pirate4x4x.com

That is a perfect example of what I have been saying. Eventhough the 6.0 GM motor is a dog compared to others such as the GM 8.1 and V-10 Ford it does just what a truck engine should do like the other offerings from Ford, Nissan, and Toyota making 80% or more of its torque below 2000 rpm. As said the Hemi only musters 63% of its torque at that RPM.

The GM 6.0 makes about 325 LB TQ at 2000 rpm which is 88%. Makes the Hemi's 240 LB TQ at 2000 rpm of its available 390 FT LB look pathetic!



Chris

 

[Diamondpilot]

I can not find the graph right now but I have a 2006 F250/F350 brochure and it states that the 6.8L V-10 makes 400 LB TQ at 1900 rpm. The engine is rated at 367 HP and 467 LB TQ so that means it makes 86% of its torque below 1900 rpm in this case. Pretty impressive for a gas truck. Again, compare it to the Hemi.

Even though I am not a GM man I will praise the GM 8.1L and give it equal time in this fight. The data on it is 330 HP and 450 FT TQ for the 2005 model year brochure I have. It makes 420 FT TQ at 1900 rpm (did this to compare it to the other real 3/4 1 ton gas truck engine). That means it makes a impressive 93% of its torque below 1900 rpm. While it does not make the HP or TQ the Ford does it has a impressive amount of torque at low rpm's. Again compare that to the Hemi.

Chris

 

[Dmace]

The engine is rated at 367 HP and 467 LB TQ so that means it makes 86% of its torque below 1900 rpm in this case. Pretty impressive for a gas truck. Again, compare it to the Hemi.

Even though I am not a GM man I will praise the GM 8.1L and give it equal time in this fight. The data on it is 330 HP and 450 FT TQ for the 2005 model year brochure I have. It makes 420 FT TQ at 1900 rpm (did this to compare it to the other real 3/4 1 ton gas truck engine). That means it makes a impressive 93% of its torque below 1900 rpm. While it does not make the HP or TQ the Ford does it has a impressive amount of torque at low rpm's. Again compare that to the Hemi.

Why in the world would you compare a Ford V10 or huge GM 8.1 liter to the 5.7 liter HEMI? Obviously, if he was looking for a towing truck that was gas powered then I would recommend those engines too but he said "My feeling is that with my modest towing demands, getting 80% of rated torque at 2700 rpm doesn't seem too scary." Sure those engines make good torque down low, they had better with that much displacement. If you really need that much low end torque for moderate towing demands then go for it, but you will pay dearly at the pump. Even unloaded you will be lucky to see 10mpg out of those engines.

The GM 6.0 makes about 325 LB TQ at 2000 rpm which is 88%. Makes the Hemi's 240 LB TQ at 2000 rpm of its available 390 FT LB look pathetic!

The HEMI makes 325lb.ft. at 2800rpms, like a whopping 800rpms is really going to be that noticeable.
The pathetic part is at about 2800rpms just as you get the load moving the GM 6.0l levels out at about 340-350lb.ft where the HEMI is making the same torque and just keeps pulling all the way to 375lb.ft. instead of "leveling out".
All these engines make good truck engines, get the job done and do it well including the HEMI. It's all a matter of preference...

 

[Diamondpilot]

He asked the first time out "Preferred gas engines for 1 ton pickups". There are 3 options, FORD, GM, & DODGE.

This is a fair comparison since they are all gas engines available in 1 ton gas trucks. Dodge has only offered the Hemi in the last 5 years or so while Ford and GM offered both a small block and big block gas engine. This clearly puts Dodge at a disadvantage.

He wants this truck to tow. He has stated that is its job and by that statement one would assume he has a daily driver. If it was used as a 90% daily driver things may be different. Of course diesel would be the preferred choice in any of the 3 brands but he is asking for gas and diesel does not always make since for all the 3/4 and 1 ton truck drivers. My uncle is a perfect example. He tows 4 times a year less than 800 miles total but when he does its heavy.

Anyway sugar coat it any way you want but Dodge is at a disadvantage with the Hemi for the informed truck buyer. Its not a truck engine. Heck, you could put a turbo 4 cylinder Subaru engine in the thing and make impressive numbers but you would be at 6,500 rpm doing so.

Like I said the Hemi name sounds cool and the high HP and TQ numbers do also but when you get down to the meat of things the short comings come out in truck applications. Yes, this sold lots of trucks, I bought one, but once informed I wised up.

While the GM and Ford engines have comparable HP and TQ numbers they go about it totally differently than Dodge. They do it with displacement. Dodge chose to do it with RPM's. As the old saying goes. There is no replacement for displacement!

Chris

 

[FlaDon]

Why in the world would you compare a Ford V10 or huge GM 8.1 liter to the 5.7 liter HEMI? Obviously, if he was looking for a towing truck that was gas powered then I would recommend those engines too but he said "My feeling is that with my modest towing demands, getting 80% of rated torque at 2700 rpm doesn't seem too scary." Sure those engines make good torque down low, they had better with that much displacement. If you really need that much low end torque for moderate towing demands then go for it, but you will pay dearly at the pump. Even unloaded you will be lucky to see 10mpg out of those engines.


The HEMI makes 325lb.ft. at 2800rpms, like a whopping 800rpms is really going to be that noticeable.
The pathetic part is at about 2800rpms just as you get the load moving the GM 6.0l levels out at about 340-350lb.ft where the HEMI is making the same torque and just keeps pulling all the way to 375lb.ft. instead of "leveling out".
All these engines make good truck engines, get the job done and do it well including the HEMI. It's all a matter of preference...

Better check your figures on the MPG out of an 8.1 again. I get better than that at 65-70MPH and with a gross weight of 15-17K in the hills. It will run 12 MPG all day long at those figures. To back it up. Okeechobee, FL to Kingsland, GA, a distance of 300 miles on 25 gallons. Kingsland to Orangeburg, SC on 17-18 gallons. And Orangeburg to Wytheville, VA on 22 gallons of Premium which actually yeilds 12.45 MPG.

 

[flusher]

FlaDon:
Thanks for the GMC power info. Great stuff.
I'll admit that I haven't been looking a GMC 1-tons lately. Maybe I should do a little homework on GM trucks, just to cover all the bases (F-series, Ram, GMC).

Here's info on the Ford engines (power curves)

Gear Vendors Under/Overdrive Ford Horsepower and Torque Curves.

just to have that info handy in this thread.

 

[FlaDon]

Here's info on the Ford engines (power curves)

Gear Vendors Under/Overdrive Ford Horsepower and Torque Curves.

just to have that info handy in this thread.

And I love this statement by them.

If you have a factory overdrive transmission and a 4.30, 4.10, 3.73, or 3.54 rear and are thinking the Gear Vendors will get you better mileage when towing - we would not agree. It is false economy to think you can tow a heavy load with just 1/2 an engine revolution per tire turn. Staying at 60mph and below are the best ways to save fuel and wear on your truck because the aero load of the typical trailer is 1/2 at 60 what is at 75mph. Factory overdrive + Gear Vendors is perfect for when the truck is not towing, but when you are towing the aerodynamics require horsepower.

That's why a 3.73 set of gears behind an 8.1 won't yeild better mileage loaded than the 4.10s. It takes HP and Torque to keep a load moving and the 3.73s actually make the engine work harder.