2001 LS1 Camaro Z28
Free Mods only
A4 Transmission.

Basically, I havn't driven the car for nearly a month until now, with the exception of a few quick trips around town but never the interstate because of a leaking water pump.

I replaced the pump and did the following:
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Cleaned out the TB since I had it out, it wasn't real dirty but I did it for the heck of it...

Cleaned the K&N Air Filter which was alittle dirty but even when it was clean I wasn't seeing milage like I'm about to post...

TB Bypass - didn't feel a difference but maybe the TB keeping cool helped?
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Anyway, I've filled it up twice since I've been back to driving it. Both times, when the needle reaches at half a tank I have somewere between 250 / 270 miles... When it is finally near E - I have 470 - 490 Miles... Thats around 28 - 30 MPG and nearly 500 Miles out of an LS1, this isn't the first occurance I've been getting freak milage either... When I was making my 50 Mile 100% Highway commutes at 70 MPH, a full tank would last me the entire week if not longer and I was pulling off 35 - 38 MPG!!! This also happened dead in the middle of June at 90 - 110 Degree Temperatures... and this wasn't babying it either as on a few occasions it did see WOT... Driving circumstances changed though and it went way down to about 25 - 26 MPG average... well... again it's even putting my V6 to shame...

50 / 50 Street / Highway...

93 Premium Octane used, usually from Shell V-Power or BP...

The A/C was not used in either circumstances nor was it used between these circumstances as it has been broke for half this year.

Seafoam the FUEL (not motor) every 2 weeks.

5W-30 Mobile 1 Synthetic changed whenever the change oil light comes on. (Currently about 1K on the oil since the last change.)

Driving speeds on road - 35 to 55 MPH
Driving speeds on Highway - 65 - 70 MPH

Not driving it any differently before, my question is, what keeps incuring these freak spurts of fuel milage? I seemingly have no control over it...

I'm not complaining or bragging but I want to know if anyone else experiences anything simular to this...

 

Well the EPA sticker on my 2.73 car says 18 city/26 highway. Before any mods I could get 28 on trips...no where near 35-38. How are you measuring your MPG? You sure your speedo is correct?

 

OMGFL, That can't be possible! I've been getting 205 miles to the tank! Cleaning the Filter helps a lot, provided you don't over oil it. -I only oil one side. Seafoam in the tank is a great investment. Octane booster helps too.. Maybe it's just a combination of everything you've done. .. Or a clogged injector..

I've only experienced the opposite.. I had a freak incident when I was getting 5mpg, but that didn't last long.

 

I have a 01 z28 ss convertable and i get 29 hwy with it.

 

I measure it by filling it up, topping it off everytime I fill up, reset the tripometer, drive it usually to 1/4th a tank and fill it up again, topping it off... recording what the tripometer reads and dividing that number by the gallons I pumped (because thats the amount that I've burned) Of course I do know my numbers can be off alittle but I don't think by much because my car has been known to hold a tank even longer than my mothers 3.2L Caddilac CTS which holds more gas than my car and usually scores in between 25 / 28 MPG according to the display panel (which I tested it once using the same method to find it was accurate.) I would believe my speedometer is correct... I got pulled over for doing 65 MPH in a 50 and thats exactly what the cop told me... I recommend you don't try that to test your speedometer though.

Edit: OH and thats the strange thing since you mentioned trips! Before the water pump broke, I drove it to North Carolina from Georgia and back... I wasn't able to score even 30 MPG, best I was able to get was 27 MPG... I was doing 75 MPH but I didn't think it would make that tremendouse a difference... It's just a freak occurance that happens once in awhile... (I was able to pull off 30 MPG at 80 MPH almost right after I got the car but that only happened once and could be subject to miscalculation too...)

 

Well I got about 23.5 MPG on my trip from Florida to Texas last week and I was doing 90-100 most of the way running about 2700-2800 RPM. I got 24.5 on my last trip from Texas to Tenn running 80 most of the way. Ill see about the way back, but thats what I usually get on the highway, with about 20 MPG city...

 

I was tickled to find my mild heads cam set-up (410 RWHP & 11.82 @117) was getting 16mpg in aggressive intown driving. Haven't been on the highway yet.

Somethings wrong. Driven very lightly a M6 MIGHT get near 35mpg if your trip was downhill. I don;t beleive it would ever get above that under any circustances.

Not calling you a liar, I'd just have to see it to beleive it.

Re'

 

keep a spreadsheet like mine then make claims.. haha

 

I understand 100%... Any method you'd like for proof? Photo's of Gas Needle position and Tripometer throughout the course? should I start keep track of records? ect?

 

I seen a pic on here somewhere of a guy getting 36mpg, so I dont think its impossible, but thats just me.

 

Nope...I'm sure you know how to calculate gas milliage, I just don't beleive an A4 can get that kind of gas miliage. Do you have 2.73 gears???

There's a slight chance a M6 could get those kind of numbers, but his A4 is supposedly getting even better than that.

Hell...My Harley only gets 40-42mpg on the hwy.

Re'

 

Yeah 2.73 gears, mostly stock except for the free mods

 

Well.........Maybe if you drive like my dead grandmother. I'd say your car is a freak of nature. I'd drive mine a lot more if it got those numbers.

Enjoy

Re'