: update on LS2 gas mileage



bjv
05-06-10, 11:13 PM
I've put 7500 miles on the truck motor, and I've recorded all of my fillups during that time. Yesterday I fed it all into excel and got some results.

About 3/4 of this is city and 1/4 is highway. My average over 7500 miles is 18.5 mpg. At several fillups I calculated right at 23mpg, the highest calculated number was 23.3mpg. The lowest numbers were 16-17.

I had been buying 87 octane until we had some discussion here about it, so I tried 93 octane for awhile. I could not tell any difference in the way the car ran. I did this for a period of 1,500 miles and over that period I averaged 18.1mpg, which is less than my overall average with 87 octane. However after looking at all of the numbers it appears that this 1,500 mile period was mostly city, in which case maybe the higher octane fuel did provide 5-10% increase in mileage.

I also discovered that if I go to the gas station quickly after my low fuel warning comes on, put the nozzle in and wait until it first clicks off, it will go about 15.9 gallons. Not knowing the real size of the tank and having pushed it too far in the past, I've been cautious about going very far with the warning on. The most I've put in so far has been 16.9 gallons.

nytoolmkr
05-07-10, 07:07 AM
car only has a 17-1/2 gallon tank.....your pushing it

odla
05-07-10, 07:28 AM
good info to know. thanks

whisler151
05-07-10, 09:37 AM
I've put 7500 miles on the truck motor, and I've recorded all of my fillups during that time. Yesterday I fed it all into excel and got some results.

About 3/4 of this is city and 1/4 is highway. My average over 7500 miles is 18.5 mpg. At several fillups I calculated right at 23mpg, the highest calculated number was 23.3mpg. The lowest numbers were 16-17.

I had been buying 87 octane until we had some discussion here about it, so I tried 93 octane for awhile. I could not tell any difference in the way the car ran. I did this for a period of 1,500 miles and over that period I averaged 18.1mpg, which is less than my overall average with 87 octane. However after looking at all of the numbers it appears that this 1,500 mile period was mostly city, in which case maybe the higher octane fuel did provide 5-10% increase in mileage.

I also discovered that if I go to the gas station quickly after my low fuel warning comes on, put the nozzle in and wait until it first clicks off, it will go about 15.9 gallons. Not knowing the real size of the tank and having pushed it too far in the past, I've been cautious about going very far with the warning on. The most I've put in so far has been 16.9 gallons.

Nice work. Do you not trust the average MPG calculator in the car?

rand49er
05-07-10, 10:40 AM
I'm not surprised that 87 runs just fine in our cars. As long as you're light on the throttle (relatively speaking) and avoid knocking conditions, it should work.

My driving is probably less than 3/4 city driving -- more like 1/4, but I consistently get 18-20 with a maggie and got 24.5 MPG @ a steady 65 MPH to V-Day I (just under 1k miles round trip) using 93 octane.

wcryan
05-07-10, 12:14 PM
I dont trust the avg fuel calculator. Mine says 11.7 : O

lilgCTS-V
05-07-10, 12:37 PM
i only get 210 miles to a tank, if i drive highway then i can get almost 300 thats what i go by. lol

CancerJCC
05-10-10, 08:23 PM
I kept mine (LS6 however) under 2k RPM on the way back from visiting the girls parents. 300+ miles with 3/4 highway and 1/4 city...got 27 mpg.

End result...Not worth the few bucks you save versus fun driving!

bjv
05-11-10, 09:24 PM
I kept mine (LS6 however) under 2k RPM on the way back from visiting the girls parents. 300+ miles with 3/4 highway and 1/4 city...got 27 mpg.

I keep mine below 2k on the highway and I get 22-23! I think I need a tune.

CancerJCC
05-11-10, 10:44 PM
I keep mine below 2k on the highway and I get 22-23! I think I need a tune.

Are you all stock? That was with the stock flash and the mods in my sig minus the B&B all the way back installed today.

Also I was using the computer MPG calculator which I have found pretty spot on in previous vehicles but never calculated it in the V to see if it is as accurate...

bjv
05-12-10, 12:03 AM
AFAIK my car is completely stock.

lilgCTS-V
05-12-10, 07:55 AM
goin 72mph from my house to nyc which is about 40 miles approx, i averaged 26.3 it was about 70 degrees out which i think helped the most.

c4ss
05-12-10, 11:11 AM
All I'm going to say is thank god I didn't buy this car for gas mileage.

ichpen
05-12-10, 03:38 PM
Don't wait until the warning flashes by. For me it means I have about 3 miles before I run dry.

Car has a high and low octane table. It will default to high octane until a certain knock retard criteria is met then it goes to low octane until you restart again.

Anyway, you can run it on 87 but it will retard timing so your mileage will suffer. Whether you save any money in the long run (cheap gas but higher consumption vs. expensive gas with regular consumption is a moot point). Bottom line run it on 91 or higher, it's what it was made to run on.

Be particularly careful if any tuning has been done. I've seen tuners overwrite low octane tables with the high octane table values.

P.S> My average fuel consumption shows 12mpg :)

lilgCTS-V
05-12-10, 05:52 PM
iv been good lately mine saids 14.1

bjv
05-12-10, 08:50 PM
Anyway, you can run it on 87 but it will retard timing so your mileage will suffer. Whether you save any money in the long run (cheap gas but higher consumption vs. expensive gas with regular consumption is a moot point). Bottom line run it on 91 or higher, it's what it was made to run on.

I had read that, which is why I did the experiment with mine. I discovered less than 10% difference in mileage from 87 octane to 93 octane, and I ran 93 octane for 6 or 7 tankfulls. I may not be pushing the car as much as you guys do but I didn't really notice that it ran any differently. However I do have nagging doubts about the absolute safety of running 87 so I may go back to higher octane. I need to contact wiat4me about a new PCM.

In some ways I don't think the mileage is all that bad with these cars. However I've gotten 22-23 highway and would be happier with 25-26. My wife's Jeep averages a little less than the V. Lots of people you see driving around in random SUV's and pickups are equal or worse than the V. I don't think the more ordinary sports sedans like the G35 do all that much better either.

lilgCTS-V
05-12-10, 09:21 PM
o but they do ^ highway cruising maybe not so much but as far as city goes they dont drink as much as the V does.

ichpen
05-12-10, 09:23 PM
I had read that, which is why I did the experiment with mine. I discovered less than 10% difference in mileage from 87 octane to 93 octane, and I ran 93 octane for 6 or 7 tankfulls. I may not be pushing the car as much as you guys do but I didn't really notice that it ran any differently. However I do have nagging doubts about the absolute safety of running 87 so I may go back to higher octane. I need to contact wiat4me about a new PCM.

In some ways I don't think the mileage is all that bad with these cars. However I've gotten 22-23 highway and would be happier with 25-26. My wife's Jeep averages a little less than the V. Lots of people you see driving around in random SUV's and pickups are equal or worse than the V. I don't think the more ordinary sports sedans like the G35 do all that much better either.

I have a wait4me tuned PCM for 06/07 btw. If you're interested. Just realised I had two.

Anyway, back on topic. Car will be running a little slower on 87. Just stick with the gas it was meant to have would be my advice.

c4ss
05-13-10, 12:47 AM
Shell V Power 93 FTW!

frdplay
05-13-10, 12:07 PM
I used to run parts back in the day for a automotive repair shop. We always ran premium fuel in trucks. In asking the owner why, he stated... "we get better mileage and cleaner burn with premium fuel. At the end of the day, it all washes out." What he meant by that was for the extra cost in fuel, the truck ran better, got better mileage, fuel burnt cleaner and left less deposits, thus providing a cleaner engine.

My wife always runs 87 octane, nothing more. Every now and then I'll fill it up with Premium, just to help clean up some of the deposits inside. Does it work... who knows, but sounds logical... so that's how I roll! :) PS.. It will cost $1.50 more to run 91 on an average fill up. That's worth it to me.

shadybx7
05-13-10, 02:14 PM
agreed.. did you guys really by this car for gas mileage:lildevil: cmmmon




I used to run parts back in the day for a automotive repair shop. We always ran premium fuel in trucks. In asking the owner why, he stated... "we get better mileage and cleaner burn with premium fuel. At the end of the day, it all washes out." What he meant by that was for the extra cost in fuel, the truck ran better, got better mileage, fuel burnt cleaner and left less deposits, thus providing a cleaner engine.

My wife always runs 87 octane, nothing more. Every now and then I'll fill it up with Premium, just to help clean up some of the deposits inside. Does it work... who knows, but sounds logical... so that's how I roll! :) PS.. It will cost $1.50 more to run 91 on an average fill up. That's worth it to me.



91... is that your Premium.. i wish that was mid grade here..NYC area has 87-89-93...

i use premium unless im in a bind

c4ss
05-13-10, 08:26 PM
As long as it's not that Cali crap they call "fuel". That stuff is more watered down than Natty Light.

CubSmurf
09-08-10, 11:23 AM
Newb here, looking at a 2006-V and have been reading the posts about the mileage. I currently have a 2006 Impala SS, and with 90% of my driving being highway I am getting a combined 19.5-20.5 Those number seem very low, considering the 28mpg on the sticker (HA)...Does the 6spd in the V help the highway mpg? My previous Vette would EASILY run high 20's on the highway because of the 6spd. Would the V do the same? Would it be optimistic to expect 22 combined with most of it highway miles? Thanks all

edwalton
09-08-10, 07:47 PM
I drive my V daily, 70 miles round trip to work - about 65 of that is good moving interstate highway. Cruise control set at 65 gives just over 21mpg average. If I keep up with traffic, I can expect just over 19mpg.
Depends on the day, the weather and the number of jerks on the road!

soflarick
09-08-10, 10:22 PM
I've seen as high as 27mpg on the highway. Between city and highway, I average 18ish. I've noticed tire pressures have a measurable impact on fuel economy.

CadzillaTN
09-08-10, 11:02 PM
had to go look.

14.8 avg, and I've been driving like an immigrant in phoenix

kevm14
09-08-10, 11:12 PM
I can average anywhere from 15 to 18 on my commute depending on my driving style. And pure highway, I thought I got 25 on my way back from PA when I picked the car up but around southern New England, I think low 20s is more realistic. That disappoints me, actually.