: Gas Mileage for stock LS6



JFensty
12-23-10, 09:11 PM
After reading some feedback on other posts about other member's mileage, it has me thinking. The best I've been able to get is around 23 on the highway and ~15 in the city. The car is an 04 and has over 102,000. I've changed wires, NGK plugs, and a panel K&N. With the mileage on the motor is there a need to check valves/rocker clearances? Possibly replace timing chain? There is valvetrain noise but I took it for normal noise associated with these motors. This is my first lsx motor although have plenty of time with older GM motors, small and big blk.
Trying to decide if there is something I should/could do as preventive and help MPG as well. If there is issues that need to be addressed with the valvetrain I would like to do it sooner than find out the hard way.. Thanks for all the input


Jerry

kevm14
12-23-10, 09:18 PM
I think that's about right. The folks who got 25 or more probably had some very flat roads. I very rarely beat 23. Does seem like it should do better, though.

bjv
12-23-10, 09:36 PM
I have an 07 LS2, I don't know how similar it is.

I checked my mileage for a period of about 5k miles and got 16.5 city and about 22 highway. I have read on the forum that with a tune I could do a bit better.

I have driven across New Mexico on I-40 numerous times, and consistently gotten at least 10% better mileage on that road than what I average around home. I don't know if it is a different gasoline formulation, higher altitude or what. So it is plausible that someone in another part of the country could get better mileage due to factors in their area.

JFensty
12-23-10, 09:43 PM
It makes sense. Was hoping it could do better tho.

What about preventive items for an lsx motor with over 100k miles. Timing chain, oil pump and the like.

Don't get me wrong, there is nothing at all wrong with it now just want to keep it that way.

Jerry

rand49er
12-24-10, 05:35 AM
I think 23 MPG highway is about right. While (when stock) I could get 26+ highway, that was what the display read while actually driving at 70 MPH. When you include starting and stopping and accelerating up to speed and so forth, the overall highway number quickly drops down to that 23 figure. Pump your tires up closer to the 40 psi level and coast a lot with the clutch pedal pushed in while in the city, and you can do 20 or better in mixed driving ... it's not much fun, though.

kevm14
12-24-10, 08:29 AM
and you can do 20 or better in mixed driving ... it's not much fun, though.

You know, you're right. I was able to get ~19 on my commute by early shifting, easy throttle, lots of clutch-in coasting. But what the hell? It's not fun at all. In the summer, driving the way I wanted, I'd get like 16. So what. But on pure highway, the highest I've seen on the display is in the 25 range, driving from PA to RI after I bought the car. Around New England the highest I've seen on the display is 24. I have magnaflow and DID have a K&N. I will be tuning the car at some point so I hope to pick up 1 or 2mpg.

JFensty
12-24-10, 09:39 AM
At some point the mileage really doesn't matter if you can't enjoy driving the car:banghead:

CadzillaTN
12-24-10, 10:28 AM
Exactly..once you discover your ranges by driving style, you realize they won't change much no matter what you do, so you end up not worrying about it anymore.. Its a natural progression with the V.

Excluding econoboxes, our mileage really isn't that far off the majority of autos on the road today.

Considering how ridiculously fun these cars are to drive, I couldn't be happier with my overall average mpg which is about 14-15 (excluding road trips)

Kev,
My best ever avg was about 19.8 and I was coasting most of the trip.

Best avg with a few romps was 16.9..

CTS_V_04
12-24-10, 02:25 PM
Buy another DD that gets better MPG HAHAHAH. I have a `98 Audi Quattro for my DD/Winter car and it gets 22MPG beating it lol. I mean beating it because its not even as close to as fast as my V. That said 22MPG with AWD city and a little high way is great. The V I get about 16 MPG mixed driving it the way it was meant, `04 V 56K miles...

rand49er
12-24-10, 09:37 PM
Yeah, having a DD that gets better MPG is the way to go.

I (unfortunately) bought an '04 Jaguar X-Type last August with a 2.5L motor and a 5-spd manual trans and AWD. I get 27 MPG with every tank in mixed driving. But like I said, this is my DD, and it's suppose to get me from point A to point B with a minimum of fuss and with good economy. If my V gets 18-19 now, I really don't care.

cts-v ls6
12-24-10, 09:57 PM
My '04 V has 170k miles and it's stock except for a K&N air filter. I have always used the cheapest 87 octane I can find, and I consistently get 24-25 mpg with the cruise set at 74 mph (about 2000 rpm in 6th gear). I average about 18 mpg in the city.

Having said that, it is fairly flat where I drive (TN, AR, MS and LA). Wind can be a big factor, by as much as 2-3 mpg. If you want to try a foolish experiment, check your mileage with the average mpg button with the cruise on, and then get as close as you dare behind an 18 wheeler. The average mpg will jump up about 2-3 mpg very quickly!

On the few times I've used premium gas, I see about a 1 to 1-1/2 mpg increase. I have averaged 27.2-27.3 mpg from Fayetteville, AR to Memphis, TN 8 or 10 times in the last 2 years, but Fayetteville has a high elevation (in the Ozark mountains) and east AR is really flat. Plus you usually have a slight tailwind. But that's a 5-1/2 hour drive, so that's pretty cool.

Jack

Lupin
12-24-10, 11:24 PM
Guys. Does a couple of mpg really phase us? We drive what is essentially a Cadillac corvette, not a prius. Neither of those marks have ever been synonymous with gas economy. The car is meant to be driven. You shouldn't be sacrificing your enjoyment or regular driving style just to save one or two combined MPG.

Black Sunshine
12-25-10, 01:10 AM
:duh:

Best I did stock on average over an 18 hour drive was 430 miles a tank. Tallahassee to Detroit. Overall avg. 23 mpg @ 78 mph, 16-17 in town.

Hamrhead
12-26-10, 04:57 PM
After reading some feedback on other posts about other member's mileage, it has me thinking. The best I've been able to get is around 23 on the highway and ~15 in the city. The car is an 04 and has over 102,000. I've changed wires, NGK plugs, and a panel K&N. With the mileage on the motor is there a need to check valves/rocker clearances? Possibly replace timing chain? There is valvetrain noise but I took it for normal noise associated with these motors. This is my first lsx motor although have plenty of time with older GM motors, small and big blk.
Trying to decide if there is something I should/could do as preventive and help MPG as well. If there is issues that need to be addressed with the valvetrain I would like to do it sooner than find out the hard way.. Thanks for all the input


Jerry

Im not too far down the road from you in Hatfield. I just picked up my '05 this past June with only 1,380 miles on it - Pretty much as new as a used car can be.

My trip to work is about 11 miles each way and makes up the majority of my driving. Generally I do ~200 miles a week. I was getting about 16-17mpg, but since the temps dropped so has the mileage - to about 15.

I could drive it like a Grandma, but as mentioned above - What fun would that be? I really don't beat on the car, but I don't worry too much about gas mileage either as using 1 or 2 less gallons a week wouldn't make much difference.

$3/gallon x 2 = $6 per week. x 52 weeks per year = $312.

Not that I'm rich, but if I'm going to worry about $300 a year, I should've kept my '09 Cobalt SS Turbo. It was just as quick as my V(Trifecta Tune 22psi/Almost 300hp) and got closer to 25mpg. Only problem was I hated it!:D

Lupin
12-27-10, 07:25 AM
Not that I'm rich, but if I'm going to worry about $300 a year, I should've kept my '09 Cobalt SS Turbo. It was just as quick as my V(Trifecta Tune 22psi/Almost 300hp) and got closer to 25mpg. Only problem was I hated it!:D

Had a beautiful girl come into my shop the other day with one of those. She said it was pretty quick, and mentioned that it got "pretty crummy" gas mileage, about 23mpg. I just smiled and said, "Don't talk to me about gas mileage," and pointed to the V.

JFensty
12-27-10, 08:42 AM
Im not too far down the road from you in Hatfield. I just picked up my '05 this past June with only 1,380 miles on it - Pretty much as new as a used car can be.

My trip to work is about 11 miles each way and makes up the majority of my driving. Generally I do ~200 miles a week. I was getting about 16-17mpg, but since the temps dropped so has the mileage - to about 15.

I could drive it like a Grandma, but as mentioned above - What fun would that be? I really don't beat on the car, but I don't worry too much about gas mileage either as using 1 or 2 less gallons a week wouldn't make much difference.

$3/gallon x 2 = $6 per week. x 52 weeks per year = $312.

Not that I'm rich, but if I'm going to worry about $300 a year, I should've kept my '09 Cobalt SS Turbo. It was just as quick as my V(Trifecta Tune 22psi/Almost 300hp) and got closer to 25mpg. Only problem was I hated it!:D

I noticed the sudden drop in MPG also,which is what started this thread. I believe it could be the cold weather blend they switched to at the gas stations. I guess I need to state a disclaimer. I really don't care about the lower MPG. I love this car and scouted around for about 1 1/2 years before I found an awesome deal. My initial worry was that something may have needed to be replaced or adjusted. Most high performance cars with over 100k miles on them usually need a little something. But since you have noticed the same drop and your car is essentially new I guess I have nothing to worry about. Now back to :burn:

Ive's V
12-27-10, 06:13 PM
I generally see around 16 mpg city and on a long trip to western PA, saw just shy of 25 mpg with the cruise set at 75 mph. I recently fixed my fuel mileage issues by buying a 08 Mini Cooper for a DD and that thing give me over 40 mpg with thrashing it constantly. It makes the gas in the V last longer too!

thebigjimsho
12-27-10, 07:33 PM
I can't get 20mpg. I'm usually around 18-19 highway and sometimes under 10 city. But usually around 13-14. But that's in my '09. My '04 got around 15-18 city and regularly 25 highway. try only getting 320 miles to a tank. I wish my '09 had a 25 gallon tank. I don't mind the low mileage, I mind the stopping for gas...

54inches
10-15-11, 11:46 PM
Great thread and +1 for me for searching. lol

I just picked up a 2005, all stock, except it has a resonator/muffler delete, which I think is killing the gas mileage. The instantaneous on the highway is only about 26 mpg at 0 mph, but I am getting about 14 in the city.


Only had the car for a few days, so I am going to run a few tanks threw it and then add some flows and hopefully things will improve slightly.

95k miles in Houston TX.

shadybx7
10-16-11, 11:11 AM
my MPG went up 2mpg or so when i did headers and tune.. on a 20hr drive from FL to NJ i got 24.xxmpg.. cruising 75mph or faster i hadn't got stuck in 4:30 DC north bound traffic, the avg mpg would have been better


I don't mind the low mileage, I mind the stopping for gas...

exactly.. i dont get why so many econ-cars have 10-12 gallon tanks.. they could have a 1000 mi range with a 25 gallon tank.. i mean they would probly blow up like pintos if they ever got hit but it sure would be a highway machine

thebigjimsho
10-16-11, 12:49 PM
Buy a Porsche 911 GT3. You get 23mpg highway and a 24 gallon fuel tank. You can drive that beast well over 500 miles...

mberisha
10-16-11, 06:06 PM
Buy a Porsche 911 GT3. You get 23mpg highway and a 24 gallon fuel tank. You can drive that beast well over 500 miles...




That is a fact....from what I heard though....the mpg for the 911 on the 'Ring is just a little less than that! :lildevil:



http://img003.picture2life.net/13553068/IMG_0809_desktop4_medium.jpg

rand49er
10-16-11, 07:53 PM
... You can drive that beast well over 500 miles...Don't you geize ever have to pee, for cryin' out loud? My "tank" will only do about 300 miles.

DougNuts
10-16-11, 09:15 PM
20-21 average, 25-26mpg 100% highway

trhs75
10-16-11, 11:26 PM
54inches -- I don't know enough about the physics of it, but I would have guessed lower exhaust restriction without the mufflers would have increased mileage rather than decreasing it. That's a layman's opinion -- someone more knowledgeable than I am can probably explain why that's not the case....

mstrjon32
10-17-11, 01:09 PM
Highway (US Legal Speeds): 23-24 MPG.
Highway (Germany, Typical): 19 MPG.
Highway (Germany, Unlimited, Low Traffic): 13 MPG.
City: 12-13 MPG.
Nurburgring: 6 MPG.

AAIIIC
10-17-11, 02:13 PM
I just picked up a 2005, all stock, except it has a resonator/muffler delete, which I think is killing the gas mileage.
Deleting the mufflers would have little to no impact on mileage.

What was put in place of the resonator when it was deleted? The resonator has an X cross-over inside it, so if someone was really cheap and just deleted the resonator and gave the car straight dual exhaust, that could have an impact on mileage.

54inches
10-17-11, 05:29 PM
Thanks for responding guys!


54inches -- I don't know enough about the physics of it, but I would have guessed lower exhaust restriction without the mufflers would have increased mileage rather than decreasing it. That's a layman's opinion -- someone more knowledgeable than I am can probably explain why that's not the case....

If the engine is tuned from the factory for that exhaust to maximize gas mileage than a decrease in back pressure COULD mess with the tune and render worse gas mileage. Not very well put, but I hope you get it.....


Deleting the mufflers would have little to no impact on mileage.

What was put in place of the resonator when it was deleted? The resonator has an X cross-over inside it, so if someone was really cheap and just deleted the resonator and gave the car straight dual exhaust, that could have an impact on mileage.

I will have to look as I think that is what he did, and I would normally disagree with your first comment, but with how long the whole system is, I would generally agree. And the fact that the dyno has proven it.

I think my issue is with the collective and not with just one part.

I am going to have to get an x-pipe if that is the case.

I am then going to ADD some flowmastrs.

Plugs, wires, air filter and a good oil change all at the same time.

We will see where it goes from there.

Thanks Again guys!

54inches
10-18-11, 09:37 AM
Well the PO of my car deleted the h-pipe when they got rid of the resonator. I found a Magnaflow x-pipe on line for $20 so I am going to have that installed when I do the flows.

BTW, for future reference, with this setup, you get a pop each time you shift threw the first few gears. GHETTO. lol

lollygagger8
10-19-11, 09:33 AM
I hit 26 on the way back to IN from NC (where I bought my V)

After the tune I can avg 23 on highway......14 in town cuz I can't stay off the skinny pedal.

thebigjimsho
10-20-11, 06:11 PM
Don't you geize ever have to pee, for cryin' out loud? My "tank" will only do about 300 miles.Get me in a groove and I can do 8-10 hours, no problem. The '09 might get 325 on a good tank and that can be as little as 4 hours. It's annoying...