Gen 3 owner, but wondering why dodge ram 1500 with v8 can average about the same mpg?

I drive vehicles for a rental car company and drove a dodge ram the other day. It was a 1500 with the Hemi and I drove 200 miles at 65/70 mph and averaged 18 to 19 mpg, my gen 3 averages 19.

 

My boss gets 13-14 mpg in his Ram 1500

 

Mine gets 20 going 75 with the 5.7 8 speed 4x4

 

That question has been asked many times before in countless threads. You will soon get countless responses and attacks from Toyota apologists but you will never get an actual answer that relates to the legitimate question you posed.

 

V8s don't have to work as hard to fight wind resistance. So at higher speeds, two objects with similar drag, the v8 will do better. at low speeds where wind resistance isn't a variable, the v6 will do better.

 

Gotta change the "if you want good mileage buy a Prius" quip to "if you want good mileage buy a full size V8 truck!"

 

Because we are in America and they wouldn't want us to get away from our dependence on oil so they get most trucks to the 17-20 mpg range and call it good.. Just kidding, I'm no expert, but I will say I rented the equivalent of a Toyota 4Runner in Costa Rica but it had a Diesel engine and it got great mpgs!

 

I kid... I kid.....

 

I had a Ram 1500 SLT quad cab as a rental for 4 days recently. Nice truck. Really enjoyed my time with it. Smooth quiet ride, very nice looking and comfortable interior, gobs of power from that sweet sounding 5.7, and no harder on gas than my Tacoma.

Are you enjoying yours Nick? What does the Big Horn package add to the SLT? Do you get the 8.4 inch touch screen and the larger driver info display? Did you go with the quad or crew? Not sure if I want the smaller back seat with longer box, or extra interior space and smaller box. Know I don't want the crew with the 6'4" box. I take a few long highway drives every year to camp and back. Usually loaded with gear and dogs. The extra space, quiet and comfort of a full size is pretty appealing. Especially with the fuel economy not being any worse, and the extra range that comes with a larger tank. The Taco never saw a fuel pump it didn't love. If I can swing it, I'll keep the Tacoma if or when I buy a full size. Just keep it at the cottage for when we fly out for shorter visits.

 

There are 2 different Big Horns. The one that I have that is just a slight step from the express and in crew cab. It doesn't have the massive touch screen or the driver infotainment system. Those are options on them that I didn't feel like paying 4-5k for.
My crew cab comes with the 5'7" box. The seats are power adjustable, chrome bumpers and such. Trailer brake controller and tow mirrors. Tow hooks are on the front. I added my own touch screen DVD player and back up camera, K&N CAI, and Magnaflow cat back, and wet Okoles. I love the truck. All it needs now is some duratracs and I'm set.

 

It's only a V8 sometimes...

 

But how does it compare to the Colorado?

 

Thanks tdnick! Great looking truck you have. Any problems major or minor? Or even just things that you find annoying? I thought the dial shifter would be one of those things, but it was really a non issue.

 

The Hemi uses cylinder deactivation at highway speeds. It essentially shuts down 2 cylinders, helping it to save fuel while running at low RPMs. The new Rams also utilize an 8 speed transmission. If you don't like all the gear hunting your Tacoma does, drive one of these through the mountains and let it change gears every 18 seconds.

 

Only thing I don't like is the shitty OEM tires. Everything else is good. Only 6k miles on it.

 

Cool. Thanks again Nick.

I found the 8 speed to be very refined. Shifts were super smooth. No clunking when putting it in gear, and no harshness when it's shifting between gears. I haven't spent a lot of time driving automatics, but this ZF 8 speed is probably the smoothest I have driven.

 

Yeah I was very impressed and continue to be. It's the same transmission that's in a Rolls Royce Phantom.

 

Sorry, I meant that in reply to the guy who comment about the constant shifting. I agree though, it's a very nice transmission, and if it is gear hunting, I certainly didn't notice. And given the terrain I was driving it through, I certainly would have.

 

Not true. To maintain speed on a flat surface with no head wind, a full size truck needs only approx. 30 hp. For an engine to generate that kind of power, you get two efficiency problems that are magnified as the engine displacement increases:

1st: What ever the size engine, they all use the same amount of air (assuming similar efficiencies) to generate that 30hp which means for larger engines that have 4, 6, or 8 cylinders physically pumping air, the larger the engine gets the more the TB has to be very nearly shut to restrict air flow. The work required to pump or force air through this slit opening equates to "Pump Loss."

2nd: Engine efficiency is dependent on the heated and compressed air in the cylinder to get an efficient detonation. With so little air shared between 4, 6, or 8 cylinders, you can see where in larger engines there isn't enough air to compress and therefore the AF mixture isn't hot enough to accommodate an efficient burn.

This is why manufacturers develop cylinder deactivation technology to increase detonation efficiency and reduce pump loss. They also have developed variable displacement engines which Toyota calls "Atkinson Cycle."



OP, the answer is extremely complicated. MPG's are not as dependent on the engine size as manufactures would want you to believe.

 

Yeah I cruise at 1700 rpm going 75. If I'm on a hill, cruise control puts it at 2000-2100 rpm. Nothing really too noticeable.