[Winkokid]

Just wondering what kind of mileage you are getting with a ls swap???Since so many of you pt"ers have done the swap, i thought this was the perfect place for this question . I drove a 2010 camaro today and it is getting 20 mpg combined. i thought a older chevelle may get better???? please tell a little about your combo ... gears, trans, mods, ect .....
Thanks in advance

 

[Matty B]

On the swaps Ive done which are typically cam, intake, exhaust, tune 5.3's, mileage is typically about 20 street 28 freeway. First the new Camaros are over 2 tons so youre gonna see a boost with even a heavy A body. Second, is the car you were driving a manual or auto. The auto gets DOD so cruising mileage goes up a bit from only running on 4 cylinders. Third, when you bump the efficiency of the motor with upgrades and tune it for a better fuel curve youre also gonna see a nice bump in mileage.

I can think of an engine swap out there that can beat the LSx for price, power, durabilty, economy and the big one EASE OF SWAPPING IT. The last reason alone is why almost every RWD platform in the world has a kit for swapping this motor into it. BMW, Porsche, Nissan/Datsun/Infinity, FORD lol, Jag and the list goes on. Its so good youre stupid not to swap it in if an EFI swap is being considered.

I am a die hard LSx enthusiast and will be until a massive architectural change is made that destroys the upsides that are here now. Direct injection may be one of those problematic upgrades for tuners and Its coming soon. As good as DI is the software isnt there to tune it right now and therefore will put off a lot of guys like us even though the bump in power and economy will be there.

Hope that is a convincing monologue regarding the pros and almost no cons of the engine.

 

[chuckd71]

I think I get a little under 20mpg with a 200-4r, 18s and 3.73 gears. Needs a tune pretty badly though.

 

[Matty B]

Sorry to add that most setups I do use a 4l60e, 3.73s or 4.11s, 26" tire. Mileage also depends on your right foot but even so Burke, one of the guys at my shop, has a 63 Nova wagon with an aluminum 5.3, long tubes, stock cam and intake along with an ok tune that has yet to get dynod with a 3.73 twelve bolt and 26" tires and he gets 22ish on the street.

With cruise control wired up you could get 30 hwy in a sub 4000# ride depending on speed.

 

[tommycomfort]

I just averaged 19.7 mpg at 83 mph coming back from Nebraska. It is a 6.2 with fairly aggressive cam and program with a T-56 six speed and 3.73:1 rear gear. I've yet to have it "tuned" but that is on my short list of things to do... I'm sure better mpg is out there, but we built it for spirited driving.
Tom

 

[thunderstruck507]

71 Chevelle
3800# street weight (tools, stereo, subwoofer, etc)
LS1 (230/224 reverse split cam, headers, Fast intake, underdrive pulley, 3" exhaust, tune)
4l60e with Yank SS3600 lockup converter ( ***See below)
12bolt, 3.42 gears
295/50r15 (26.5" tall)

19-22 mpg highway depending on ethanol content, speed, and elevation changes

***At 70mph, the engine is under such a light load with this combination it is hard to keep the converter locked which negatively effects fuel mileage. At 75mph it is easier. I recommend a 3.55 or 3.73 gear as a possible solution to this issue.

 

[andrewb70]

I got about 21 MPG on a long road trip this summer. The car was over 4000 pounds loaded with two people and luggage.

6.2L engine with a LS7 cam well tuned, 3.73 gears, .62 overdrive, 27 inch tall tires.

Andrew

 

[Aceshigh]

Over 20+ mpg city is VERY hard to believe......
Even supremely light and aerodynamic C5 and C6 Corvette's don't get that with 6 speeds. :noway:

Mine
1978 z28 with 2004 GTO LS1 / 4L60e, 3.42 gears and 25.6" tire
Harness and PCM mods done by Speartech.

Roughly 20mpg highway on a 320 mile trip from St Louis back to Chicago ~75mph.
My last tank was some bad gas and I got 11mpg so I can't vouch for my city mpg.

Nothing was changed internally to need a tune, but obviously something is amiss with the City MPG.
I'm currently putting a 2008 LY6 6.0L with a T-56 6 speed in my 1970 442.
We'll see how that one turns out.

 

[novaderrik]

Over 20+ mpg city is VERY hard to believe......
Even supremely light and aerodynamic C5 and C6 Corvette's don't get that with 6 speeds. :noway:

Mine
1978 z28 with 2004 GTO LS1 / 4L60e, 3.42 gears and 25.6" tire
Harness and PCM mods done by Speartech.

Roughly 20mpg highway on a 320 mile trip from St Louis back to Chicago ~75mph.
My last tank was some bad gas and I got 11mpg so I can't vouch for my city mpg.

Nothing was changed internally to need a tune, but obviously something is amiss with the City MPG.
I'm currently putting a 2008 LY6 6.0L with a T-56 6 speed in my 1970 442.
We'll see how that one turns out.

city driving for you might be different for me.. i live in a mostly rural area, with the biggest city in the area having about 13,000 people and 5 stop lights where the car is never stopped for more than about a minute at a long light in what passes for "rush hour".. someone that sits in big city rush hour traffic will get lower mileage..

 

[camcojb]

64 Chevelle
twin turbo LS402
4L80E with lockup converter
3.25 gears
25.7" tires

300 mile round trip averaged just over 21 mpg at 65-70 mph (had wife with me ). Not fully tuned yet at that time, but close.

 

[smitty454]

I dont like reading about these LS swaps because it makes me regret everything I have done to my chevelles powertrain especially in times like these with the gas prices as high as they are. LS is the way to go.

 

[buddyholly]

I get 17mpg around town with the A/C on. I have not done any real long highway road trips but I am guessing at around 21mpg highway from what I have done.

 

[Matty B]

Over 20+ mpg city is VERY hard to believe......
Even supremely light and aerodynamic C5 and C6 Corvette's don't get that with 6 speeds. :noway:

Mine
1978 z28 with 2004 GTO LS1 / 4L60e, 3.42 gears and 25.6" tire
Harness and PCM mods done by Speartech.

Roughly 20mpg highway on a 320 mile trip from St Louis back to Chicago ~75mph.
My last tank was some bad gas and I got 11mpg so I can't vouch for my city mpg.

Nothing was changed internally to need a tune, but obviously something is amiss with the City MPG.
I'm currently putting a 2008 LY6 6.0L with a T-56 6 speed in my 1970 442.
We'll see how that one turns out.

Well as far as a 5.3 is concerned it seems to be doing just that.. Thats a stock internal L33 (the aluminum one). A lot of things affect MPG street and highway. Right foot is the biggest one obviously. If you have a mileage computer youll notice that a lot of start and stop is REALLY bad on economy. Second is how much pedal you give it even making small acceleration changes. Short hopping every car screws things up too.

Now for combination issues as well as possible mechanical mess-ups. Things that may not seem to be a big deal like swapping an intake manifold with different injectors than what the IFR (injector flow rate) table is setup for can cause you to run hideously rich. A MAF that is screwy will also mess up mileage. These things can be easily verified with a scanner (not a code reader) and looking at the long term fuel trims.

The stock PCM can add over 25% more fuel than what is called for depending on problems in the system. Say you have a combination of a bad maf and tired o2s. Lets also assume that they are at the verge of setting a code but dont which is called "failed in range". Now to jump over to the computer part, there is Long term Fuel trim "LTFT" and Short term Fuel trim "STFT". The PCM looks at the sensors that measure air predominately to develop a fuel trim. In a perfect world, the PCM would never have to adjust fueling from what was originally programmed as base tables. We dont live in a perfect world. To deal with that the PCM adds or subtracts fuel to get to the spot the base table says it should be at. From the start`the motor is running at 0% trims. within a minute or so short term trims start modifying fuel a little bit. After little more time the PCM figures that 6% STFT isnt changing so It makes a global shift of the fuel trim by 6% and STFT starts over at 0% again.

Ok now say we have some bad sensors. Lets start with just a bad MAF. It reads more air than it should but not enough to set a code for it. It reads that X amount of air is coming in so the PCM adds Y amount of fuel and the o2s read Z amount of air in the exhaust. Since more fuel was added than what was needed, a good set of o2s will catch this and will see it as too rich. After a while a code would set for being too rich or in a borderline scenario the LTFTs climb to compensate until the computer reaches 25% LTFT and finally says enoughs enough theres definitely something wrong. At this point a code is set for either being to rich or the MAF isnt working right.

Now say you have some 02s that arent working great as well. Instead of reading what is going on exactly or damn close, it reads closer to normal than it should. This is a problem. Now we have one sensor going bad and another sensor that cant tell that its bad. This is the perfect storm for bad economy, subpar performance and NO CODES!!!

Being that most swaps are used swaps its not out of the question that most of the sensors are old and iffy as well.

If youre getting 11 mpg stock motor then something is seriously and I mean SERIOUSLY wrong. Grab a scanner and look at the LTFT.. Perfect world is less than 3% if you spend most of your time in the same area doing the same driving. If youre over 7% then you need to do some looking.

I know this is a weird spot for a tech article of sorts but its a big reason why your mileage could go to sh it.

 

[1971Z16]

Over 20+ mpg city is VERY hard to believe......
Even supremely light and aerodynamic C5 and C6 Corvette's don't get that with 6 speeds. :noway:

Mine
1978 z28 with 2004 GTO LS1 / 4L60e, 3.42 gears and 25.6" tire
Harness and PCM mods done by Speartech.

Roughly 20mpg highway on a 320 mile trip from St Louis back to Chicago ~75mph.
My last tank was some bad gas and I got 11mpg so I can't vouch for my city mpg.

Nothing was changed internally to need a tune, but obviously something is amiss with the City MPG.
I'm currently putting a 2008 LY6 6.0L with a T-56 6 speed in my 1970 442.
We'll see how that one turns out.

my friends 1998 Z28 Camaro gets 22mpg in the city and 30mpg on the interstate, and i know a guy that has a 2009 Z06 7.0L Corvette and it gets the same mileage with an extra 200hp, so most of it doesn't matter about the horse power

 

[Matty B]

my friends 1998 Z28 Camaro gets 22mpg in the city and 30mpg on the interstate, and i know a guy that has a 2009 Z06 7.0L Corvette and it gets the same mileage with an extra 200hp, so most of it doesn't matter about the horse power

CHURCH.

A stock motor should get AT LEAST 20 mpg street. Cams and heads and big injectors dont count here although its possible if the tune was spot on and you hypermiled it lol.

ACESHIGH- Have you ever checked your Speartech tune? If you told him the wrong injector size or messed up on some other specs your fueling would go to sh it. Also I hope you are just assuming that a c6 cant possibly get mid 20 mpg cause it happens all day when driven like a daily.

If you have HPTuners Id be more than happy to look over your tune based on your setup. PM me an .hpt file if you have one. Im sure I could see something screwy if its in the tune. No I wont tune it just point out mistakes if there are any I notice. Otherwise Id contact Speartech and ask them to double check what you gave them for info vs what they put in the tune vs what either of you may have screwed up on.

Personally I think a hardware issue is at fault like a bad injector, a bad MAF or the like is to blame.

PM if you have any questions with what I said. Send a few good pics of your engine compartment and full specs as detailed as possible and Ill give my best go at shooting you in the right direction.

 

[johncolvin]

I average 20MPG in mine - stock 2001 Camaro Z28 LS1. I have 4L60E trans and 373 rear. It really sings at 80MPH
Regardless how I drive it, I pretty much get the same because of the rearend ratio. If you want better mileage, go with a 330ish gear. If you want to launch hard and burn up some rubber, I recommend the 373!
With my setup, I get better milage around 55-60MPH but it's so hard to do that because everything around me is interstate.

Also, when I park, I don't drip, leak, puddle, smoke, etc. I leave the parking stall the same as I found it. No carbs to tune. Get in, turn the key and go! I drive it every day it doesn't rain...oops, it's raining now... Looks like that is out the window also. Awesome reliability!

 

[93Polo]

2000 C5 LS1 stock shortblock no flycut pistons or upgraded rod bolts
LS6 intake stock polished throttlebody
Kooks 1 3/4" long tubes
3" to X pipe 2.5" after no cats
Futral F11 228/230 112+4
TEA Stg 2 5.3 heads
Double roller timing chain
GM oil pump modified by Futral

436rwhp/415rwtq 29-31mpg hwy with 3.42s and M12 ratio 6spd, 16-17mpg around town being relatively easy on it. Hwy mileage went up from 27-28mpg after heads and cam but I think that is because I went from passing in 4th to using 5th as a passing gear. I wasn't trying to get mileage on these trips

I pulled 18-19mpg stock being easy on it around town. An exGF did get over 20 in her stock C5 6spd. My heavy '01 6.0 LQ4 2500HD crew cab pulls 13-15mpg around town. So I could see 20mpg around town as possible but the tune would have to be dead on and the driver would have to be soft on the loud pedal.

If mileage were my concern I'd go with a 6speed, and build the smallest bore motor I could get the desired power out of. The 5.7 is a nice compromise. Also tq across the band helps and my car with the 2.5" after the X made some great torque #s down low. A friend had the same setup with 3" turn downs on an F-body. The f-body's peek rwhp was about the same but his peek rwtq was down 10 from mine and much more low in the band (where you cruise).

 

[zipsimons]

I average 20MPG in mine - stock 2001 Camaro Z28 LS1. I have 4L60E trans and 373 rear. It really sings at 80MPH
Regardless how I drive it, I pretty much get the same because of the rearend ratio. If you want better mileage, go with a 330ish gear. If you want to launch hard and burn up some rubber, I recommend the 373!
With my setup, I get better milage around 55-60MPH but it's so hard to do that because everything around me is interstate.

Also, when I park, I don't drip, leak, puddle, smoke, etc. I leave the parking stall the same as I found it. No carbs to tune. Get in, turn the key and go! I drive it every day it doesn't rain...oops, it's raining now... Looks like that is out the window also. Awesome reliability!

Hey Jon.. I have the identical set up going in my 72. I'd love to see more pics and hear more stats about yours!

 

[johncolvin]

I'll see if I can get some more pics up. I just finished the center console which turned out great (that is me tooting my own horn )

I also drove an '04 vette for a couple of years and I got 31 MPG on a road trip running 85 MPH. It's mostly highway with some city driving. 510 miles on a tank of gas with 1/16 left (no gas light warning yet). You can't beat the LS1 performance and gas mileage abilities.

 

[zipsimons]

I'll see if I can get some more pics up. I just finished the center console which turned out great (that is me tooting my own horn )

I also drove an '04 vette for a couple of years and I got 31 MPG on a road trip running 85 MPH. It's mostly highway with some city driving. 510 miles on a tank of gas with 1/16 left (no gas light warning yet). You can't beat the LS1 performance and gas mileage abilities.

I'd love to see that console and any other pics you might have!