17.8 calculated MPG on last tank...Meh

[Turbolq4]

My DD is a Hondork Accord that gets right around 30. '96 f250 'stroke does 15-18. '81 granny Malibu, LS swapped with large hairdryer gets 20s iffin I drive it nice like, gets low single digits if I beat on it. Ol ladies' Highlander gets 20.

New efficient engines are great!

 

[Gwarren79]

Hypothetically, you could put a tbi system on it from the 2.8 S10, run 4.3 injectors and get over 20mpg.

 

[CaliWagon83]

I found this that they say works on the 231 2-bbl: https://www.affordable-fuel-injection.com/product/buick-tbi-complete-system/

I don't think I want to screw around much more with the current engine. Longer-term plan is still the LS3.

 

[olds307 and 403]

I got 21 Imperial mpg which is identical. That was in my 70 Cutlass, Olds 260, non lock up TH350 with 2.78 gears and tall 215/7514 tires. Same combo with a 2004R/3.42 gears and shorter 235/60R14 tires 26 imperial mpg. Hoping for 30 imperial mpg with the 215/75R14 tires and a serpentine setup.

 

[DRIVEN]

305/200-4r/3.42s gets me 20 pretty consistently on the freeway. Occasionally 21. I don't even track it from tank to tank, just long trips.

 

[olds307 and 403]

Driven I am only 1 mpg ahead with less power. Hopefully I won't loose mpg putting back on the headers and dual exhaust, it made a huge power difference, so I will risk it.

 

[olds307 and 403]

My DD is a Hondork Accord that gets right around 30. '96 f250 'stroke does 15-18. '81 granny Malibu, LS swapped with large hairdryer gets 20s iffin I drive it nice like, gets low single digits if I beat on it. Ol ladies' Highlander gets 20.

New efficient engines are great!

It is not just the new engines, everything from the 6, 8 or 10 speed trans, which always keeps the motor at the most efficient rpm, also the diffs as well are designed for low friction and has thinner synthetic fluid factory. Heck, I gained 5 mpg going from a 2010 Dodge Challenger 3.5/5 spd to a 2017 Dodge Challenger GT AWD 3.6/8 spd. The AWD adds a 400 pound weight penalty and it is still a good 1/2 second faster in the 1/4 mile.

 

[PBGBodyFan]

Finally checked mpg on my wagon, felt like it was poor and it sure is, 12.7 mpg on this the first full tank of gas I've used. Car starts/runs pretty well and smooth, it's been about 20 years since I had a 3.8 2bbl but feels maybe more sluggish than it should under acceleration. Bone stock 3.8 with 200-C, lockup isn't working so that might account for a couple mpg, 2.73's.

 

[fleming442]

I was getting 19 out of my 3.8 Series 1 with the CCC 2 bbl. The Series 2 gets 23, and is much faster.

 

[Huen79H/O]

1979 hurst olds 350 olds/350 turbo no lock up stock rear diff.
Drive it 60 miles a day gets 16mpg with ac on the same as my 03 Yukon