gas millage-what gives?

[Russ M]

Since my snake was new the gas mileage has never been better than 12mpg, even cruising it on the highway. For the most part it has been about 9-10 my foot is a bit heavy

.

Well the other week the check engine light came on at 7500 miles, so I went to reset the ECU by unplugging it and disconnecting the battery. Mind you that I have several times in the past attempted to make the ECU relearn by disconnecting the battery for 5 min. Well anyway after this was done the check light was gone, figures it was a service warning. However there was another unexpected change the gas mileage!

It was like flipping a switch suddenly the car is getting 17mpg!!! Now don't get me wrong I am all for it, but does this seem normal? How and why would resetting the ECU make this happen? And, how does the car still seem just as quick with obviously less fuel?

Thanks

 

[BigsViper]

Perhaps it was running too lean before the re-learn?

No Observations - Just Flames.

<FONT size="2">(credit for this sig goes to serious...)</FONT s>

 

[dadsvpr]

being i am averagin about 10-12 i would be interested too. btw, what kind of mileage people getting? i don't really care but it seems like between 8-15mpg on a tank. depends how heavy i'm getting into it obviously.jason

 

[onerareviper]

Russ,

If your only getting 10 MPG on the highway, there is a problem. Driving in 6'th gear, easy on the gas - highway, close to 20 MPG. Now I rarely feather along in 6'th gear. My average is 12-14 MPG with a mixture of everything - City, Highway, and violent bursts of speed to (somewhere in the triple digits..

Later

P.S. - Running to rich can be caused by many things. I was running way to rich (Bad 02 sensor and MAP sensor.) Of course, reseting the computer would not fix these things....

 

[bitya]

I must drive like a girl. Most trips are min. of 300 miles was getting since new 25 to 27 mpg after trinket mods (454 rwhp) getting 23 to 25 mpg, if I run in the 80 to 90 range it ranges from 19 to 21 mpg.

 

[lleone]

I just did a super cruise trip, 400 miles, 70-75mph,
mostly in 6th and got 22.6mpg on my way there and
20.8mpg on my way back. (OK, I may have been going
a little faster on my way back.)

 

[rhansenjr]

I agree with the above posts. Driving reasonably around town yields 14-15 mpg. Trips in 6th gear are always better than 20 mpg. I have reached 25 mpg several times on flat freeways with no wind(or maybe a tail-wind).

 

[Go Hogs Go!]

My 2001 GTS gets 13 miles per gallon in town, and 17 in sixth cruising at 75. My 93'RT/10 gets 15 in town and 21 cruising in sixth. The extra 50hp makes a difference in the mileage.