what did you do for getting that good mpg?

 

my freinds 350 pulls 15-16 all day long. the 350 in my truck was doing 13-14 just because it was much heavier. all depends how you drive, if you have heavy feet it will show

 

ok im not much of a mechanic so bear with me..lol i have an 86 305, i havent had it long and i bought it with "50,000" miles (im sure its more) but anyways im only getting about 14 mpg, it needs some work done but will a good tune up get more mpg and power?

 

Well tuned with clean air filter, synthetic oil, transmission fluid & differential oil, properly inflated tires, SLP Dual/Dual cat-back etc my 305 TBI/700R4 RS normally gets 28-32 mpg on interstate highway trips. Best ever is 33.5 mpg.

How one drives also effects MPG.

 

I have a 305 TBI that has the 700R4 tranny, but I have an exhaust with the muffler cut off, and the stock air intake with the cover flipped over. I have Bosch Platinum 4+ plugs and Bosch Premium O2 sensor. Replaced the spark plug wires and cap/rotor, running premium fuel, I have gotten up to 31 MPG on the freeway. Going 70 MPH the whole way.

 

http://imgur.com/llKAp

Now this is not as awesome as the before mentioned 30+ mpg. I was running 059 vortec heads, gmpp intake, ebl system w/tune, newer plugs, old plug wires (with later known busted ignition coil wire), 2.73 open dif. I would like to add this was a roughly 100 mile sample heading hwy 29 south from omaha to kansas city. It's a pretty flat stretch of land and I was averaging 70-75 mph light foot on the pedal. Overall, I averaged 22 mpg on 1.7k mile trip to Richmond Ky from Omaha,ne. First tank of gas was 89 octane (cheaper in NE) then ran on reg 87 octane.

 

it seems to me what you need for the best gas mileage is a t56.i realize it will take a while to break even.

 

i do all highway driving and im getting spring/summer i get 23/25 highway. When the temp get into the 30/40s it drops to about 15/18