dude i cant do it at the same gas station after a 150 mile trip, i dont drive in circles. Im not that worried about getting perfectly accurrate results for a message board, sorry. I calculated what i did, if you dont believe it fine. your reasoning is a lot better than "33 mpg just cant happen" as has already been said. there is indeed some 'fluff' in there as you say, but i can only say i did my best to avoid that.

 

weight is not going to affect highway mileage nearly as much as aerodynamics. 4th gen fbodys are some of the most aerodynamic vehicles ever produced IMO. When i let off the gas in my truck at 85 it feels like I hit a wall. In my camaro on the other hand i can float along at 95 mph like its a walk in the park.

the fact that many people including myself get the best mileage at or above 80 mph backs that up even further. most vehicles start guzzeling above 70.

 

Thats almost impossible. Unless you drove around 50 mph. Sure you calculated right? My car has K&N FIPK, Hooker Aerochamber, running 91 octane and i have never gotten any better than 23 driving 65 mph ..... w/ 2.73's

 

sounds like you have stock manifolds (headers gave me nearly 3mpg), and an automatic. big differences right there, youre going to be turning a higher rpm than me even with the 2.73. my buddy has a car setup similar to yours and has managed 26mpg more tha once.

also, i only run 93-94 octane. i wont even use 92. also as ive said before, i get my best mileage about 80mph. 50 would be worse, in fact 50-55 is probably the worst speed range for a 6 speed car: too fast for 5th and too slow for 6th.

 

i got roughly 29.5 mpg on the freeway at 85 cruise from vegas to fresno,452 miles to the tank and i promise you the tank was EMPTY when i got there!



my mods are simple:
CAI
STOCK MANIFOLDS
TRUE DUALS,X-PIPE 2.5",1-CHAMBER FLO's
ALUMINUM DRIVESHAFT
C6 WHEELS 19X10.5 & 18X8.5
LS1 BRAKES
SYNTHETIC FLUIDS
NO CUSTOM TUNE
RUNS 13.86-14.1 2400'-3200'DA VEGAS HEAT!

 

Sorry to say, but you are wrong... I fill my car up the same exact way every fill-up... Maybe my mathematic skills are not up to par and maybe you can do the math for me, what is 357 divided by 10.023?

 

My math skills are pretty solid and I believe that would work out to around 50 mpg.

My car used to get upper 20's on the interstate. And I always had 5-6 hoes up in there. It would be nice to experience an increase in mpg after I do my exhaust.

 

I dont think anyone here will believe that you got the best MPG out of anyone here all while averaging over 100mph..... or maybe you miss read your odometer and you actually travelled 257 miles which is a more believable yet still not possible in my book of 25.7 @ 100+ mph. I will wager my car that you cant reproduce those numbers. ill even let you drop the speed to a more reasonable average of 85mph. you prove it and my car is yours........

 

Speedo could be off. Thats my guess. My stock LS1 98 Z28 Auto 2.73 gear car barely got 30 MPG on the highway. And that is an LS1 which gets better milage than LT1's. My LT1 on a killer day at its best is still right at 28 MPG highway. That doesnt happen to often.

 

your right foot has alot to do with fuel economy.

 

I get about 26 on the highway

 

Especially in the rain when my car is more sideways than it is strait going down the road

 

Snow works really well for that trick too

 

Tricked-Out-Toy - NICE RIDE!

sam Pace-

I tried driving like a schmoe in a Honda for a full tank (you know, egg under the accelerator thing, wasn't fun) It really didn't change much. One thing I did notice.

No ac, about 210 miles and one gallon left at fillup
A/C on I got about 190 miles and had 1 gallon left at fillup
After running AC on the previous tank, and no AC on the current I would get 230 with one gallon left. 245 with the car sputtering to the pump


I get about 70 miles before the needle gets to the full mark, then after that it gets to 125 at 3/4 mark, then 160ish when I get to half. After that I get to 185 at 1/4. then I get paranoid and find a gas station.

 

357/10.023 is not 50mpg buddy, its about 35mpg.

when i towed my trucks bed behind my car and my car loaded down iwth crap back to school at the beginning of the semester after doing my headers, tune, and ORY i only got 16mpg highway. it seriously felt like i was towing a parachute behind me, because normally going down one hill on I68 if i put it in neutral at 80 ill accelerate to about 95 pretty easily, with the trailer, i slowed to 65! i did a trip tuesday to court down I79 through the mountains and got 27mpg. i think the added power from the headers/ORY/tune, and pulley helped though cuz i no longer ever have to downshift from 6th through the mountains. i think thats the main reason everyone is getting better mpg after header install.

oh and the result from the trip to court, was fighting a ticket of 91mph in a 60 and a $256 fine, cop didnt show so it got dismissed!