What to buy? V6 OR V8??? (for Silverado Z71)

[MetroMPG]

The v6 and v8 get almost identical mpg

Don't forget that when you're talking about a 16 MPG vehicle, 1 MPG is a significant difference in volume/cost of fuel used. See post #5.

figure in the v6 gets driven harder to perform the same, its a tie.

I see this repeated often, and I'm skeptical. Sounds like a truck drivers urban myth /slash rationalization.

- The EPA test cycles run the engines at the same rates of acceleration and same speeds (ie. "perform the same"), and the smaller displacement engines win out over the bigger ones.

- For "real world" results (if you assume the sample size is big enough and representative), check the "Your MPG" numbers on the www.fueleconomy.gov site and I bet you'll find that smaller displacement engines also get better MPG as reported by real drivers

Pre-emptive point: anecdotal stories (lacking solid methodology) don't count!

[woodydel]

I bought new my 2007 Chevy Silverado with 5.3 litre and 315 HP to pull my Nash travel trailer. When not towing, the V8 will beat any V6 offered in MPG. Taking advantage of the offered fuel management system is the key. On the dash, the display will indicate when you switch up or down in cylinder cutout. With a simple glance at the dash you can control your foot to keep the engine in 4 cylinder operation. You cannot feel the changeover. It is flawless in its operation. That is how I could easily bring in 26+ MPG on the highway brand new on the New Jersey Turnpike at 65 MPH and even on small country roads it is easy to hit mid twenties. The next training feature as I call it is the instant MPG display. Once you have trained your foot to not be a lead weight, the next step is to maximize the MPG. Instant MPG is accurate. The trucks's computer always knows exactly how much fuel is entering the cylinder. It also knows exactly how far you have traveled. So as I'm traveling down the highway, the majority of time I am in instant MPG mode on the dash. My method works and I can always beat the EPA rating by a wide margin.

For those who like to coast, the instant MPG readout really makes you feel good. Instant gratification 99 MPG going downhill coasting.

The V6 did not offer this feature of fuel management. Plus is could not tow my Nash trailer or more correctly was not designed to tow so much weight.

GM has had the best design for economy for several years. They don't get enough credit for this.

Not that I did this but this engine can really haul A**.

[bhazard]

I dont know why you guys bothered with this kid. He's obviously too immature to take in any advice you might give him, he only wants to hear what he WANTS to hear. Like get a big lifted V8 truck and it will automatically get 30 mpg when you put loud exhaust and a cold air kit on it. If you disagree you are WRONG!

Big Truck Ego. Thats all. *spits dip*

[MetroMPG]

woody: your story illustrates how your truck would benefit from aerodynamic mods (aero shell! partial grille block) much more than a non-cylinder-cutout version, since you'd be able to enter 4-cyl mode sooner, and hold it longer. (Assuming it's a load-dependant thing.)

And it suggests that a 4-cyl truck would be even better than a 6- or 8-cyl one. (Ducks for cover!)

[MetroMPG]

Originally Posted by bhazard

I dont know why you guys bothered with this kid.

Oh, I think most of us gave up talking to him after his 2nd post.

Think we're talking amongst ourselves at this point. Nobody here but us chickens!

[Angmaar]

I gave up after I heard cold "air intake and exhaust" and fuel efficiency in the same sentence.

[woodydel]

Well, I'm in the process of figuring out how to streamline my Class A motorhome. It's GVWR is 18000 lbs and the GCWR is 26000. It's got a Ford V10 and currently averages 10 MPG. That's at 55-57 MPH on the highway. It's 32 feet long and there is all kinds of stuff sticking out of every surface top, bottom and sides. I know here 10 MPG is considered horrible but I can remember way back when a Ford pickup with a crew cab would get 8 MPG. First I want to make skirts for the rear tires and second some type of air deflectors for the tires front and rear. The front tire air deflectors I'm thinking to be part of a pan across the bottom down as low as the front axle height. The front tire air deflector would also streamline the front axle. In order to do this, I have to keep the coach looking good. My wife is not going to tolerate cardboard panels as we travel. I have already posted about this motorhome on this site. The rear needs work to smoothe out the air flow. I carry a 250 cc scooter on back so it has to accommodate the scooter's being taken on and off the rack.

My underside is aerodynamically a nightmare. My idea is to keep the air moving around rather than under the motorhome.

The Chevy is only driven intermittently and streamlining it might not happen. Over a three year 4 month period I only drove it 19000 miles. Which by the way is the best way to economize. To NOT drive unless necessary. This happens to be contrary to my overall driving record. The 1999 Mazda B 4000 which the Chevy replaced currently has 195,000 miles on it. That's a lot of fuel I purchased. The best I ever got in MPG was 19. It still gets 19. When I could get fuel without ethanol it would just clear 22 MPG. Even though the Chevy beat it by a wide margin, I still stopped unnecessary driving and even then the scooter is my first choice.

My opinion about the OP getting upset is he just wanted to know what to choose. He did not want to justify the type of vehicle. Maybe he got help from what I did with the Chevy. My son with the same year truck from GMC doesn't give a damn about economy. It has all the same features but he just doesn't seem interested. When in his truck with him driving, he can't stand my questioning his driving habits as far as economizing goes. So to see someone interested enough to ask questions is a good thing.

[tim3058]

Originally Posted by MetroMPG

Don't forget that when you're talking about a 16 MPG vehicle, 1 MPG is a significant difference in volume/cost of fuel used. See post #5.

I see this repeated often, and I'm skeptical. Sounds like a truck drivers urban myth /slash rationalization.

- The EPA test cycles run the engines at the same rates of acceleration and same speeds (ie. "perform the same"), and the smaller displacement engines win out over the bigger ones.

- For "real world" results (if you assume the sample size is big enough and representative), check the "Your MPG" numbers on the www.fueleconomy.gov site and I bet you'll find that smaller displacement engines also get better MPG as reported by real drivers

Pre-emptive point: anecdotal stories (lacking solid methodology) don't count!

Yep, I just generalized they are a tie for purpose of saying he won't save much with the v6. But I checked fueleconomy.gov after your post, it does list 1mpg EPA rated difference for the auto 4.8l v8 vs auto 6, but same avg mpg for manual 6 vs manual 4.8l 8. Under $180 savings/yr if he went with the auto 6cyl. Thats less than 10% saved going with the auto 6, nothing saved for the manual 6. I still say its a wash, a gas truck is just plain bad mpg

[ShadeTreeMech]

Originally Posted by MetroMPG

woody: your story illustrates how your truck would benefit from aerodynamic mods (aero shell! partial grille block) much more than a non-cylinder-cutout version, since you'd be able to enter 4-cyl mode sooner, and hold it longer. (Assuming it's a load-dependant thing.)

And it suggests that a 4-cyl truck would be even better than a 6- or 8-cyl one. (Ducks for cover!)

I wonder what an inline 4 diesel with a 10 gear manual would do for mileage. Or even a 4 cyl gasser with an electric motor for power assist and start stop technology.

[NHRABill]

Originally Posted by euromodder

A couple MPG simply won't cut it when starting out with a gasguzzler.

Something is better than nothing I am 25% better than EPA chart saving 39 gallons in the past 2300 miles I have driven.

I guess a couple gallons is better than none at all