LS9 little about it
http://en.wikipedia.org/wiki/GM_LS_engine
DoC

 

600 hp or more!!!!

jeez...

 

Yes, it will be supercharged....AKA LST... So much for mileage.

 

What are you talking about? A properly designed blown engine can get great milage. I get 30+ highway on a 300+ WHP Grand Prix GTP with headers, cam, gears and 17+ PSI of boost. Now if I put my foot in it, it goes to 7 MPG, but that's true with most performance vehicles.

 

You guys know that any joe blow can add/change the wikidpedia encyclopedia? Look at it now. I wouldn't really believe what you see on it.

 

So your saying GM can't design engines? I have yet to seem them make a gas v-8 engine get 30mpg ave. in a real world driving schedule....now cram more air/fuel into it.....i doubt the LST will be any different. I'll let you know when i hear more. BTW, your comparing a 300-400hp engine to a 600hp production engine.

I work in the auto industry and i can tell you that most of the truck applications get horrible mileage 17 in a LQ4/LY6 HD pickup on the highway. H2 gets even less than that....15mpg. I had a 76 Chevy 4x4 blazer that got better average milage then that. It even had 150K+ on the odometer. Granted you could still kill yourself with the exhaust gas, but hey, we should be able to breath straight exhaust gas and be ok right?

The LST is going in the HD trucks, but not in 08 trucks as it stands right now. I was speaking in the context of vehicles that it will be put in from GM when it comes out....not aftermarket. The engine will probably trickle down to some cars, but not sure how the hood lines will look. GM's marketing dept. may have their hands full there.

GM seems to be wrapped up in a power war with, apparently Dodge, for what ever reason. They really need to put their efforts in to figuring out how we are going to make engines more efficient when run on ethanol and how we are going to make enough ethanol to support the demand they are helping to create. And where are the hybrids...yea, i know there are mild hybrids in the LD trucks, but what 5 years late to the party isn't bad.

 

There's a reason the trucks don't make good mileage...and it has little to do with the engine. Just stand in front of one and look at the size and shape of what you're pushing through the air. Not to mention the weight. The same engine that gets 25 mpg overall in a Corvette would do well to get half that in a Silverado and even less in a Silverado HD.

 

My car gets 30 mpg all day long on the hwy at 60 mph in 6th gear.

 

Yep and that's why i said average mpg. Add another 100-200 hp to that and increase in displacement .2L and see what you end up with....w/supercharger your average mpg will be in the crapper. It's true, you only need a fraction of the engine's power to maintain cursing speed. But unless they are planning to be able to cruise down the highway at 900rpm or less good luck getting any better mileage with the LS9.....heaven forbid you need to accelerate.

org....Yep, basic aerodynamics. Your point being? I still don't see average mph over 30mpg....v-8 car or truck. Your only getting that kind of mileage because of the aero and, mainly, the rpm reduction in the trans and crusing at a lower engine speed. In 30+ years there has been basically no advance in average mpg(given the same size v-8 car/truck). You either need to make it lighter or change fuels. The vette may be the only exception but the customers are paying for the technology up front and even that is about as far as it going to go.

"Yea, it gets 60mpg, but i don't touch the gas, the engines off and i'm going down hill while slipstreaming(Drafting for the nascar crowd) a semi"

 

I don't understand . You mean I should add 100-200HP to my current 621 and add .2L to my current 6.6? And then I'll see really bad mileage? I had thought that my current set-up has bigger displacement and more HP than what we expect the LS9 to have...yet I still average an easy 30 mpg on the Hwy in 6th at 60mph. Point being, if you stay out of the boost, FI cars don't use much more fuel than a NA motor.

 

i get an honest, true 19MPG with my old tech LS1... with a cam.... some tanks are higher... one week we had hard rain everyday, and i got 25MPG... just from having a lighter foot.
but i get an honest 19MPG on every tank. and thats more then any performance V6 car or truck.... or 4cyl truck i know of in this area with similar driving.
the LS series motors are truly efficent motors... they may get sucky MPG, but they also are making the power while doing so... if you want great MPG, you need to ask GM to do the same thing i am.. tell them to make a CAR that is LIGHT and put the engine in that.

 

LoL I love how you guys are arguing about MPG in a performance car...who cares...I cant imagine any of the potential buyers on a blown v-8 sportscar worrying about gas MPG...

 

All I know is thats going to be one bad *** motor when it comes out, hopefully if they produce the Corvette SS it will have that in it

 

Yeah but the mileage

 

Exactly. If it takes 60 hp to move a non blown car at 70mph, it still takes 60 hp to move a blown car at 70 mph. The only loss would be the power used to turn the blower, miniscule. That's why 6.0 HD trucks and 8.1 HD trucks get about the same mileage cruising at the same speed.

 

If you add a SC to a LS1 Corvette the only 2 things that change is the performance...which is much better (125 HP) and the fuel economy (goes down 2 mpg)..I have a friend that had his done to his car and those were the changes that he saw..he now gets 27 miles per gallon at 65 mph instead of 29 miles per gallon...but if you have your foot into it it will use more fuel just like any engine will..anyone buying the car is not going to be concerned about fuel economy anyway...the LSx series engines are very fuel efficient for V8's..especially in aerodynamic vehicles ...don't get mad at GM about the gas situation..they did not sell us down the river to the oil company's..blame good ol George Bush..he is collecting big time from his oil company buddies..the lame duck prez is getting his that is for sure..

 

you dont know what you are talking about do you? do you even OWN a Gen III powered vehicle? and if you do, have you owned a Gen I or Gen III powered vehicle? if not then you have no idea how much more efficient the LSx engines are versus their predicesors(sp?). its not a very accurate comparison but my dad went from driving a 350 (Gen I SBC) powered 87 silverado 2wd to driving a 4wd 4.6 liter sohc 97 F150. i think he averages about 5-10mpg more per tank in this truck than he did in his old one. it would be even more of a jump if both trucks shared the same drivetrain configuration (2wd vs 4wd).

i used to get 15mpg or less in my 91 L98 trans am (again a first generation sbc) to a 94 z28. the z28 is not running yet but i do expect to get 25+mpg on average. its the biggest reason i didnt put an lt1 back into the car like it came with. i want to drive it a lot and the power and efficiency the ls1 has cant be matched by an lt1 of any sort. im also expecting around 420-450rwhp off the bottle with this engine as well.

to say that v8 efficiency hasnt changed over the past 30 years is a very innaccurate statement. trucks now are getting better in town gas mileage than cars 20-30 (even 15) years ago couldnt get on the highway. and thats comparing trucks to cars. one thing i feel should be helped is the v6 passenger car arena. with v8 powered cars hitting 20-30mpg in any driving situation and trucks hitting 15-20mpg under most driving situations, the v6 efficiency NEEDS to be stepped up IMO.

 

That's why it should be turbocharged.

 

Exactly!!

 

Hmmm I wonder if the actual motor with Have DOD,now that would be funny as hell.

Introducing the latest and greatest corvette - supercharged 600hp with displacement on demand for 35mpg at 65mph on the highway.

ScottyRocket - you talk about your old 4x4 getting better mpg then the modern hd trucks. You are corrrect.

Take a look at the curb weight of your old 70's style truck and compare it to the new HD's and the H2 is worse due to the fact that it's heavy like 5000lbs and shaped like a brick (the 2 biggest things that kill gas mileage).

Major things that can affect a vehicles gas mileage.
Air resistance of the vehicle (over the body and under the vehicle), Total Vehicle Weight, & Part Throttle Tune (where the motor stays at 75% of the time)... oh and tire width/size can affect gas mileage as well (wider tires offer both more resistance to the ground as well as air resistance).

Tuning has alot to do with how good or bad a vehicles gas mileage will be.

Take a look at an LS2 powered C6 Corvette thats had an exhaust system and a good tune, they'll hit 30mpg or better on the highway as long as they are fed 91 octane or better.
Even cam'd with a stage 2 heads an LS2 can hit 30mpg as long as the computer is tuned correctly.

The LS2's by default run very rich throughout the power band (and its in the part throttle where that hurts the gas mileage on LS2 power vehicles). And that part throttle gets hit hard once you start adding on exhaust parts or Intake kits without tuning... LS2 ecu's will go from rich at default to rich and retarded with cai and exhuast if you don't retune (so you loose power and gas mileage).