Efficiency of the LS1/LS6

mattr762 · #1 (**permalink**) 11-19-2003, 02:48 PM

The Corvette LS1/6speed gets 18/25mpg while the LS6/6speed gets 19/28mpg. These engines are light, fuel injected, drive smooth, provide awesome power and get great gas milage. Does Ford have an engine to compete? Or can a ford engine be built to compete (cost effectively)?

How much of that good gas milage is from the rear diff gearing?

blykins · #2 (**permalink**) 11-19-2003, 03:30 PM

Sure Ford has one to compete...the 4.6L engine does fine...as a matter of fact, on long trips I usually get 23-24 mpg in my Mustang GT...with a 4.10 rearend...

blykins · #3 (**permalink**) 11-19-2003, 03:31 PM

By the way, why do you ask?

mattr762 · #4 (**permalink**) 11-19-2003, 06:41 PM

No offence, but I know the 260hp Mustang GT does NOT compete with a 405hp Z06. It's a 1.5 second difference in the 1/4 mile.

The Mustang Cobra 390hp is much closer, but it must use a supercharger to get it there and it still get worse gas milage.

The reason I ask is because I've heard a couple of cobra owners complain their cobra is a little rough to drive especially in traffic. And plenty of them have mentioned only getting 5-10 mile per gallon. So, I figure if I put a modern high performance engine in my future Cobra then I would enjoy it as a daily driver a little more.

SVO460 · #5 (**permalink**) 11-20-2003, 01:01 AM

I agree with mattr762. The 4.6 isn't even in the same league as the Chevy motor (and it hurts like hell to say that being a die hard Ford man). Less mpg, less hp. Even the 5.4 needs a blower to come close in hp. Why Ford, why <sobbing>?!?!?!?!
Check out the Ford Australia site. They have mid and full size rwd cars with IRS, but we don't. They have a Falcon GT (the mid size rwd) from their FPV (Ford Performance Vehicles, their version of SVT) with a 5.4 32 valver making 290kw which if I figured it right is just about 390 hp.........naturally aspirated!!! That's better then our supercharged Lightning.

blykins · #6 (**permalink**) 11-20-2003, 07:55 AM

Well, he wasn't asking about horsepower...he just asked if there was an engine made by Ford that came close in mpg...I was just putting in my $.02. I think 23 mpg is pretty good for a V8 and a 4.11 rearend.

I think Matt's missing out on one of the qualities of a Cobra though. It's not meant to be a Cadillac, where you just sit and recline with cup holders and 30 mpg...It's a muscle car for goodness sake. It's supposed to be mean, loud, shaky, and poor gas mileage. That's my opinion anyway.

I'd really like to see, however, an LS1-LS6 that got 28 mpg...I'm sure GM would like us to think that, but in ideal situations, I'm sure it's not up to that par. I have several friends with LS1 Z28's and T/A's....I haven't heard them speak of the LS1's great gas mileage yet. You usually buy a V8 for one reason...power...not fuel efficiency.

To answer the second part of Matt's first question...I'm sure a little bit of it could be contributed to gearing.

GM cars usually have a 3.42 rearend ratio...It that case it wouldn't be putting such a burden on the engine on street traffic...plus it would be high enough (especially with a 6th gear) to cruise on interstate at around 1200 rpm. That's probably how these cars can get any gas mileage at all. They're basically idling at 70 mph. On the flip side, most Mustangs have a 3.27 rearend and only 5 forward gears. To take an engine that makes all its power and torque high up in the powerband, it's pretty stupid to gear the rearend up that high. You wouldn't believe what a low gear does to these cars...So taking off in street traffic, you're faced with putting a pretty big load on the engine to take off and get up to speed...that's not too easy on gas mileage.

I don't know...there are probably several ways to look at it, but those are my opinions.

Turk · #7 (**permalink**) 11-20-2003, 08:17 AM

Sadly the milage claims may be acurate.

Drove a 2002 Corvette for 650 miles or so. Average speed for entire trip well over posted speed limit. Back roads of Nevada.
When I arrived at my destination, trip computer indicated 26.5 miles per gallons in spite of the type of driving I just experienced.

TURK

mattr762 · #8 (**permalink**) 11-20-2003, 08:22 AM

blykins, I do appreciate your opinion and everyone else. That's why I ask the question.

Quote:

Well, he wasn't asking about horsepower...he just asked if there was an engine made by Ford that came close in mpg.

Sorry if I wasn't clear on this, but I was referring to the high power output while getting good gas milage.

Quote:

I'd really like to see, however, an LS1-LS6 that got 28 mpg...I'm sure GM would like us to think that, but in ideal situations, I'm sure it's not up to that par.

My dad has a Corvette 405hp ZR-1 that consistantly get 26mpg on the highway, so I'd say it's very possible for the newer LS6 to get better than that.

Quote:

I think Matt's missing out on one of the qualities of a Cobra though. It's not meant to be a Cadillac, where you just sit and recline with cup holders and 30 mpg...It's a muscle car for goodness sake. It's supposed to be mean, loud, shaky, and poor gas mileage. That's my opinion anyway.

Hmmm.... Interesting opinion and that is definately one way to look at it. But if you could have the best of both worlds would you do it? With modern technology you could have the mean sound, loud and shaky while getting decent gas milage. Most of these replica car makers are updating the suspension so it handle better, so why not put in an engine that makes it a better daily driver (something the wife could drive).

Remember, muscle cars aren't suppost to handle very good either.

blykins · #9 (**permalink**) 11-20-2003, 08:39 AM

Matt...

Let me get some things clear before I go on...I want you to know up front that I'm not trying to argue or slander anyone's car or opinion...I was just stating some things that I have learned and felt.

I guess I wasn't clear on what your original statement was, and I'm sorry for misunderstanding. Unfortunately, I guess Ford isn't up on power and gas economy. One of my friends has a 2003 Cobra...I'll check and see what he gets. It's not exactly showroom stock anymore though...he's running in the 11's...hehehe...

I do think the rearend ratio has a lot to do with it. My Dad's 97 Cobra and my Mustang both get around 23-24 mpg on trips. Both of them have 4.11's....and Dad's dyno'd at 326 to the tires. I think you're asking for it if you're making a high-rpm motor labor at low speeds and revs. Maybe with a middle-of-the-road ratio like a 3.55 or a 3.73, the mileage could be optimized.

I'm a Ford man myself, and as bad as I hate to admit it, the Z06's do run well. I drove a 385 hp one back when they came out...very impressive.

I still hold my stance though on the roughness of a Cobra. :-) My theory is that these are toys...not really meant to be daily drivers. There are a bunch of guys that do drive them as such though. Hal has a ton of miles on his...and it's a pretty healthy stroker motor. I myself would not choose the best of both worlds. My Cobra is a weekend toy, and it's gonna be just that. I have other cars that I can depend on for economy. I also think that it's sacrilege to put a GM motor in a Ford automobile, so that kinda nips that in the bud as well.

I think you'll see that there are two types of people that own Cobras...some want just a toy that's as fast as can be...others want a "replica" of an old American muscle car. To have a replica, it needs to be as such...big block Ford V8...carb'd up....4-speed Toploader tranny, etc. To have a Cobra with a Chevy engine would just make it an ordinary "kit car"....along with all the chop top 32 Fords out there. I just can't think that way. Actually, I wouldn't even put a fuel injected Ford engine in a Cobra...hehehehe...

I currently have a stroked small block Ford...but the more I thought about it, the more I became purist. The small block will stay in there until the car is 100% complete, but I have an FE big block sitting on the engine stand right now. :-)

Again Matt, I didn't mean to come across as a crass person....just expressing my opinion. Hopefully I've given you another testimony to decide with. One thing for sure...whatever Cobra you end up with, you'll have a ton of fun. :-) It doesn't matter once you get in the seat and take it for a spin. It wouldn't matter if it had a 5hp Briggs & Stratton and it was painted hot pink with stripes....hehehe...

cruzin' · #10 (**permalink**) 11-20-2003, 11:03 AM

Sorry guys.. . . I have a 02 convertable and it gets 20 mpg with combined city and highway. . .and when you set the cruise at 65 from detroit to cincinnati. . it gets 29mpg. But,... I want a cobra too. . I'm looking at getting a Lonestar or BDR for the wife soon.

NVM

SVO460 · #11 (**permalink**) 11-20-2003, 11:17 AM

blykins, I agree with you about keeping the correct engine for the car, even if it's a kit '32 deuce, it "should" have a Ford motor. But the Cobra (not to open up a can of worms but I can still see the lid opening...) is not really a Ford. Sure since the early '60's their history is firmly intertwined. Since we're all Cobra freaks here we all know the history no need to repeat the England/Shelby thing. Would any one consider the Panzos a Ford or a Checker a Chevy?

On the same note, in the mid west it's in the mid-upper '60's and I had my '67 Ranch Wagon out. I'm restoring it but wont get to the paint until next spring so it's a little weathered. Some guy comes up to me in Menards lot and starts with the usual.."...my parents had one when I was a kid....". I mentioned I was restoring it and he said I should keep the paint as is and make a sleeper out of it "...and like put a 502 under the hood."
AHHHRRRRGGGGGG! Yes, I was thinking about running him over after that!

PSB · #12 (**permalink**) 11-20-2003, 11:50 AM

If you prefer a Chevy engine in your Cobra - go for it. Getting the six-speed tranny to fit is a challenge, but can be done, depending on what kit you get.

If you want a Ford, how about a fuel injected 351W stroker? There are several guys at The Corral that are claiming to get in the 20s for gas milage with 400-500hp fuel injected 351W strokers and a 5-speed tranny.

Pete

cscott67 · #13 (**permalink**) 11-20-2003, 01:11 PM

The mileage claims are true, as my c-5 gets more than 26mpg on the freeway during trips. Scott

TCR_BRIAN · #14 (**permalink**) 11-20-2003, 01:55 PM

The LS1 is an awesome motor, alot of engineering is in that motor, head design (Stolen from a Cleveland Ford),program etc, just don't start modifying it, unless you get a 6.0L truck cast Iron block, as the aluminum blocks suffer from Core Shift and failure once you start putting boost or N20 into them, or just making some good power....As far as MPG Vs. HP, its all in the cam, final drive ratio, and programming, mostly the programming....I think GM spends more time in this area than Ford. You start running DFI and playing with the programs watch out... One of my friends has an 89 Mustang LX 306 NOVI 2000, 15 PSI, full cats, air pump etc, with his emmisions program gets over 25 MPG, and has made a best of 720 RWHP, has gotten over 150 HP just from tuning his PMS system with Wide band O2....Other friend 95 Camaro Z28 Convertible , LT1 stroked to 396, FAST DFI, 12:1 on 93 Pump Gas (Gotta love reverse flow cooling), 3500 Stall w/lockup 3.73 rear, has ABS, A/C, drives like a factory car, his wife drives to work all the time...Race weight 3980 lbs... went from 12.40 with stock computer, and got 20-21 MPG driving to and from the track, to 11.96 and 27-28 MPG driving to and fromt he track, with tuning and FAST DFI, same car, same track, same skinny ET streets on stock rims...This was @ Lebanon Valley which isn't the highest, but you will run 1-2 tenths quicker @ Englishtown than Lebanon......anyways LS1 great motor in stock trim, not a good one to modify heavily, tuff to keep clutches in them, but awesome power and extremely smooth....Fords 4.6, John Coletti said it best a couple of years ago when they built the Super Snake and I even said yeah right at the time "The 4.6 is going to make the OHV V8 (302/351 etc) look like a Flathead when the OHV V8 was introduced in terms of power." By the way how many people do you see driving a "Stock" Mustang Vs. a Stock Corvette, isn't that why we buy Mustangs, Bang for the Buck and Aftermarket......I did.....Gotta play with em'....

Brian

www.teamcracing.com

408cobra · #15 (**permalink**) 11-25-2003, 08:42 PM

The ls1 and ls6 are nice motors and also have the benifit of being aluminum blocks but lets be honest here as far as efficiency the US based companies are way behind european engine technology. Even the ls-6 is old school pushrod technology. BMW has been making more horsepower per cubic inch and better gas mileage than anything detroit has dreamed up. I love american V8's but I also drive an Acura tl types that gets 260hp from 3.2 litres with variable valve timing. A stock 5 liter ford made 225hp thats pretty lackluster without comparing mpg.

mattr762 · #16 (**permalink**) 11-25-2003, 11:17 PM

Quote:

but lets be honest here as far as efficiency the US based companies are way behind european engine technology. Even the ls-6 is old school pushrod technology. BMW has been making more horsepower per cubic inch and better gas mileage than anything detroit has dreamed up.

HORSEPOWER
Acura NSX 3.2L = 290hp (17/24 mpg) 90hp/liter
BMW M3 3.2L = 333hp (16/24 mpg) 104hp/liter
Corvette Z06 5.7L = 405hp (19/28 mpg) 71hp/liter
Mustang Cobra 4.6L = 390hp (17/24 mpg) 84hp/liter
Ferrari 360 3.6L = 400hp (11/16 mpg) 111hp/liter
Jaguar XK XK8 4.2L = 294hp (17/24 mpg) 70hp/liter
Lexus SC 430 4.3L = 300hp (18/23 mpg) 69hp/liter
Lotus Esprit 3.5L = 350hp (15/22 mpg) 100hp/liter
Subaru STi 2.5L = 300hp (18/24 mpg) 120hp/liter
Maserati Coupe GT 4.2L = 390hp (11/17 mpg) 92hp/liter
Porsche 911 Turbo 3.6L = 415hp (15/22 mpg) 115hp/liter

If your talking horsepower per liter then the Subaru win hands down. Now if you look at the displacement vs torque then there are some surprizes there!

TORQUE
Acura NSX 3.2L = 224tq 70/liter
BMW M3 3.2L = 262tq 81/liter
Corvette Z06 5.7L = 400tq 70/liter
Mustang Cobra 4.6L = 390tq 84/liter
Ferrari 360 3.6L = 275tq 76/liter
Jaguar XK XK8 4.2L = 303tq 72/liter
Lexus SC 430 4.3L = 325tq 75/liter
Lotus Esprit 3.5L = 295tq 84/liter
Subaru STi 2.5L = 300tq 120/liter
Maserati Coupe GT 4.2L = 330tq 78/liter
Porsche 911 Turbo 3.6L = 415tq 115/liter

What was my point again? Oh yes, is smaller displacement that important to you? Because if it is then you should go with an STi!

The LS-6 does get better gas milage than any other performance car while still making gobs of horsepower and torque.

tonyvda · #17 (**permalink**) 11-26-2003, 06:02 AM

Modern technology, lots of power with good economy is just what I was looking for hence my use of the BMW 4.4 litre V8. A bit of work on the exhaust manifolds ( headers) to free up the flow and youve got over 320bhp with 30 mpg on a run.

With petrol/gas at over $5 per gallon we have to watch our petrol consumption over here. If your fuel prices had been like ours over the last 30 years all your manufacturers would have been using using aluminium engine and multiple overhead cam technology many years ago.

Cheers,

Tony

Art Burtt · #18 (**permalink**) 11-26-2003, 07:25 AM

My '88 Corvette with the 4+3 trans will get 30 mpg on the interstate crusing at 65-70,but who cares about mileage when you're "crusin" in a Cobra. I'd be afraid to use mine as a daily driver because I wouldn't be able to park it and watch over it.
Do many of you use your Cobras as daily drivers?

SVO460 · #19 (**permalink**) 11-26-2003, 08:34 AM

The horse power per liter/inch is the same lame argument the ricers always use. Bottom line is what makes it to the wheels (preferably rear wheels <VBG> )
So what push rods have been around longer, does it mean they are some how not as good? It works, it works very well.
Look at the massive amounts of horse power a chip and some minor tweaking will get you from a Turbo V6 Buick. That design is almost 20 years old and imagine if they kept it around with just some updates and revisions what it would be making today? It would embarrass every new car today. Doesn't matter if you use push rods or OHC as long as the results speak for themselves. Hmmm any one want to guess how long OHC design has been around???

Satanpez · #20 (**permalink**) 11-26-2003, 02:14 PM

LS6 all the way. And I'm a Ford guy I guess.

It's lightweight being all aluminum, makes great power and gets good gas mileage.

5.7 liters? Who cares. Look at the 4.6 Ford motor. It's 1.1 liters smaller in displacement, but have you ever seen how HUGE that engine is? How insanely heavy and complex?

Want high power per displacement? Go look at a weed wacker.

-steve in nj-