wannafbody

iTrader: (2)

I put an Airaid intake tube on my 2009 Silverado. It removes the helmholtz resonator. It probably adds a couple HP but under throttle it adds lots of sound.

Darth_V8r

iTrader: (4)

Interesting! I had a friend at work who was getting plumes of oil every time he came out of DOD to full performance on a 5.3 in a monte SS. We tuned out his DOD, and it quit doing it. At first I was thinking his PCV was causing it. i'm wondering about valve seals now, except it doesn't plume at start up, which is usually the dead giveaway for valve seals.

Hadn't thought about the 6-speed transmission. but I also remember a while back, GM stayed with the 4 speed way longer than others, because they were getting the same MPG on 6-speed trans as with 4. Coulda just been market speak for "we don't want to" :/

Could be as simple as larger bore makes more torque, so you're just not in the throttle as hard to hold speed. but, then that gets back to the OP - why the 6.0 is so thirsty?

you know if this was some guy posting his H/C package, getting underwhelming performance and poor mileage, we'd all be telling him the heads and cam were poorly matched. Hmmmmm.......

tech@WS6store

iTrader: (2)

Gotta add gear ratio and gears when looking to accelerate the land yachts they build now. amd get mpg also. only problem is no real 1:1 ratio.

00pooterSS

iTrader: (40)

Yes we would, and that would be efficiency. The 6.2 is obviously more efficient whether alone or as a total package with trans and potentially more items.

That smoke thing though, just weird. I would think it was getting confused on fuel during the change over.. maybe.

00pooterSS

iTrader: (40)

I still wanna hear from a VHO or SS owner that drives for mileage. But then again, that's an LQ9, higher compression, more efficient. But a half ton with a 4L60

big hammer

6.2's in my experience are always as good or better on fuel than a 5.3. And WAY more power. And yeah the combustion chambers of the l92 heads are better

Tuskyz28

I clearly understand the statement. But if bore eats mpg.... why does 6.2 gets better gas milage over the 6.0 and the 5.3 ? 🤔

LLLosingit

iTrader: (4)

Efficiency, It doesn't matter if it's a 4-6-8 cylinder, It takes X amount of force/power to move an object and the one that is most efficient will use less fuel. I took a 4.3 4l60e (17mpg) out of my S-10 and it probably made around 170whp and put in a 6.0 with a supercharger and a 6-speed. around 500whp and my mileage went up quite a bit.

RedRocketZ28

iTrader: (19)

This is what I would like to know. I would guess that the 6-speed trans attributes to some of the MPG gain. Also, the higher compression ratio certainly doesn't hurt either.

I actually have someone coming to look at my 1500HD tomorrow. I threw it up for sale for what I thought to be a high price just to see if I got any hits before winter. We will see what the guy thinks of it but if he wants it I will let him have it if the agreed upon price is still a decent profit for me. I had no intentions on driving it this winter (haven't driven it in three weeks) and if it does sell I will be looking to get into something newer, with more power, in the spring.

I have found a couple of NNBS 6.2L Crew Cabs within 200 miles of me that have less than 65k miles on them. Not sure if it would be smarter to get something like that in the low 20k range or see if I can get a 14+ Silverado with the 5.3L in the mid 20k range with similar mileage. I have driven a NNBS truck but have only ridden in a 14+ truck.

I just hate pulling our boat with the 6.0/4L80E combo. Leaving it in 3rd gear and screaming down the highway, only getting 7-8 MPG, isn't what I enjoy. I know it's not hurting the truck at all but I still think it should pull better than what it does. Like I have mentioned before in this thread, a 5.3/6L80E Tahoe felt a lot better pulling the boat than my truck does.

Tuskyz28

I keep on forgetting GM put 6 speed automatic tranmissions behind the larger 6.2 engine.
I guess it's a major help after all if not car companies wouldn't be going to 8 speeds etc...

But yet I'm still impressed with the 5 speed manual 6.0 mpg the fella mentioned earlier in this thread. After all it's only a one gear difference between the 4L80E and the 5 speed manual.

00pooterSS

iTrader: (40)

Large bore doesn't always equal more fuel. Direct injection, higher compression, more efficient head design, cam design etc are all players. Lower viscosity oil, less pumping loss, lower parasitic loss (pwm alternators and electric power steering) the list goes on. Then throw in DOD and 6 and 8 speed transmissoins. It all plays

But one simple breakdown too. If you have a 9:1 5.0 and a 11:1 6.0(hypothetical numbers) and lets say a more accurate tune on the 6.0 with something to the effect of what they used to call a fast burn head (more efficient chamber) and the 5.0 has a sloppy chamber and poor burn qualities the 6.0 will kick the 5.0's *** in efficiency equating to higher output and lower fuel usage.

Think - how much energy is being extracted from the amount of fuel being put in. The more efficient motor extracts more energy from the same given amount of fuel

Direct injection takes this even further. And if you really want to see even more of this go over and read up on Mazda's sky activ system. They run super high compression with really funky looking pistons and are making high power with high mpg. It's all about efficiency.


GM may even be running these newer big motors leaner, they have done away with EGR and AIR injection through advances in cam designs and computer tuning, but at a sacrifice for power and efficiency I bet. I wound't be surprised if they have gotten the cam/tuning/head design tech even better to where it still is emissions compliant yet they've figured out some efficiency stuff too. VVT and DOD help but I bet on the basic cam design itself they have made improvements and maybe some allow a leaner burn with still meeting emissions; running lean causes higher cylinder temps that raises NOX, that's what EGR valves were for, maybe they were able to do it all?? I'm really reaching now..

I know the direct injection allows for a lower amount of fuel to be used and still have the same output and general afr range. Because they can get more burn out of the same amount of fuel input.

00pooterSS

iTrader: (40)

Make sure you drive a 2014+ truck first. The NNBS trucks feel good but there's an unparalleled level of refinement feeling to the 14+

I keep looking at the 07-13 trucks and want a 6.2 truck BAD but man the 07-13 truck feels cheap in several ways to me and I work on them a lot. And all the things I do to them that I've never had to even consider doing on my 04 keeps discouraging me from getting one. There's things I love about them and hate. The 14+ trucks won't be in budget till next year so I'll wait to upgrade my truck or just keep mine forever. The newer gen trucks don't hold up as well as the NBS truck did. The NBS was one of those vehicles a manufacturer just got everything right on as far as durability. Everything lasts almost forever on them. I've had some 14+ come in with busted a/c lines and/or condensers with low mileage and googling it it's a common issue. Like 10-30k low mileage. It's frustrating when you're considering buying one and having owned a NBS that's at 190k and only needed a water pump and that's it in it's whole life. Other than that just maintenance.. rear brake pads, belts and fluids, and tires. Not a single thing else. Not even front pads yet.

RedRocketZ28

iTrader: (19)

Good point. I am not sure the NNBS would be worth the extra money at this point. I really like the 16+ front end but those trucks aren't in my price range right now. I think I'd be extremely happy DD'ing and towing with a NNBS 6.2L though.

My 03 1500HD only has 56k miles on it. I just wish it pulled better and got slightly better MPG. I also have a few little quirks with mine that I really need to address. One being that the ABS kicks in while coming to a stop and the other is the converter unlocking at highway speeds and will take a few miles to lock back up. This continues over and over.

wannafbody

iTrader: (2)

14+ 4 wheel drives have a vibration issue. My 09 Silverado is smooth as butter driving down the highway.

Larger bore, larger engine doesn't necessarily eat fuel, case in point, I own a 4 cylinder Miata that probably gets 18-20 local and 28 on the highway. My TA gets about 18 local and I've gotten 27.5 on the highway. 1.8L vs 5.7L, you'd think that the 5.7 would use far more fuel but can run down the highway at 1200 rpm vs 3000 rpm for the Miata.

G Atsma

What people don't realize is it takes only so much energy to push a car down the road. And once rolling, size ALMOST does not matter. The difference between pushing a Miata or a Gen 4 TA is not much. The 4 cyl has to work harder, hence 3000rpm for it vs. 1200 for the TA. It does help that the LS is a VERY efficient engine design. You made a good point!

tech@WS6store

iTrader: (2)

I've got an 08 2500hd 4x4 with ly6. It does about 12-14 loaded or unloaded. And drives much worse than either of my gmt800s

00pooterSS

iTrader: (40)

To be honest the main reason I gave the finger to looking at NNBS 6.2 trucks was the price. I looked at Denali trucks and people want 20k plus for a nice one, generally 23 or so. I found a handful of 2014+ Denali trucks in the nation with 100k for 29-30k. I'd much rather have the newer truck for an additional 100-150 bucks a month. It's a chunk of change but way worth it IMO

interesting
comparing 2500 to 2500?


So i'm slow at work watching lots of engine masters and things they test like H pipes long tubes vs manifolds etc and got to the mechanical fan test. That's a good one to watch and made me start thinking of parasitic loads. The newer trucks use pwm alternators and electric P/S that will equate to power and MPG

My point.. I ventured over and looked at underdrive pulleys for trucks. I could only find ASP but they advertise 12-15 hp which eh it's a truck but they advertised 2-3 mpg.. Which is possible if it reduces parasitic draw.. Might be a worthy investment on a truck

Tech@ws6 are there any other underdrives for 5.3/6.0 trucks?

wannafbody

iTrader: (2)

My dad's 08 6.0 2500 HD rides like a brick. I really hate driving that truck. They have replacement cab mounts that might help slightly.

His lifetime mileage is 12.5

tech@WS6store

iTrader: (2)

Im running a 25% underdrive on truck. It. Sucks. i have a 145 amp alt and my coolant temps do crazy **** and its hard for me to even jump a car or battery off. Do not do it.

All my trucks are 2500hd 4x4.

I wish powerbond still made the stock sized truck pulley. They only make stock replacement and underdrive.
Diving into the other stuff esp from engine masters is a rabbit hole in left field for any dd tow haul truck.

Better tires are where i saw big gains. Not only in mpg but handling and overall driving.

RedRocketZ28

iTrader: (19)

Yeah, the couple local ones I found are a 2010 with 61k for $23,900 and a 2011 with 65k for $22,900. I gave $15,500 for my 2003 1500HD with 52k on it. I currently have it listed for sale for $17,250 and the guy coming tomorrow says he has cash and has been looking for a clean 1500HD. No idea if he's interested in it at that price or not but I won't go any lower than $17,000. If I sold it at $17,000 it would pretty much be a wash after traveling to get it and paying the taxes back here in Iowa. I've only put 4k miles on it but have used it for its intended purpose over this past summer. Not sure if I would be stupid for getting rid of it or not but it's also not going to get driven for the next few months.

I will be in a better position to get something newer come spring/early summer though. Still not sure I'd want to swing a 14+ though and a lower mileage NNBS with a 6.2L may be the best option at that point still.

I probably should have kept my 2004 5.3 Rainier for another year or so!