This should be a big thread. What is everybody getting for gas mileage. List your combo engine/trans/rear GR. My old 70 skylark 350 convertible got 11/17 with a stock 350-2/TH400/2.56 rear. My 70 455 convertible currently gets 11mpg with the bronco pulling it from Georgia to illinois.(sorry I had to do it).:laugh:
12 in town and ~20 on the highway if I am not mean to it. Stock short block 71 455 with Stage1 heads, TA headers, 2 1/2" exhaust with X pipe and dynomax muffs. Rebuilt Qjet. 3.23 posi rear. I maxed out at 23mpg on the highway going up to Flint....I think that was a shining moment in my old car driving history to get that kind of mileage out of a big block!:Brow:
Adam, you sure those #'s haven't come down a bit now that you have the 3.23 :laugh: . I got 17 on the highway, doing 80, w/ no backseat or spare. I got about 13 on the way back, car packed w/a good 200-300 lbs of stuff, which included some local driving as well. That's w/ a stock 455/TH400, 2.73 open rear, small-body HEI, rebuilt Q-Jet, dual 2.25" exhaust. As stated, that's w/ a stock 125,000 mile motor, so there is room for improvement.
http://www.v8buick.com/showthread.php?s=&threadid=23040&highlight=Gas+Mileage I'll refer you to my answer in this thread about gas mileage. :TU:
I don't pay as much attention to mileage as I did the first year I had my 68. Interstate driving 70mph from OR to ND I ranged from 19 coming out of the mountains, to mid-teens on the flat MT roads. These days I probably have combined hwy/city of around 13 maybe??? Pretty stock 71/72 350-4 with TH350 and 2.56 posi. Car still has the newer 625 Carter carb that was on when I bought it, but I'm planning on swapping on a 750 Qjet in the spring. That may improve my mileage, unless I keep my foot in it... may be putting 15's on in the spring too. Truth is, if I was worried about mileage, I would drive a Honda. Although periodically checking gas mileage can give you an indication of tuning issues if you see a dramatic drop.
28 mpg Ok, my speedo is 20 mph off, so that should equate to around 18. That was freeway driving. Not with the Holley, but with the 800 cfm Quadrajet. 455/400/3:42 gears and still made a 11.95 pass last month. Now with the Holley, I get around 6 mpg.
Never bothered measuring my older vehicles, but the 86 regal can get between 21 and 23 MPG. This is a combined city and highway milage. My F-150 used to get 19 MPG combined, now its down to 13 MPG combined. It has 120,000 very hard miles. It still runs though. Not good or bad, but it runs. The F-250, when it was road worthy, got around 8 MPG. Now it uses about 1/2 gallon of oil between startups. It has a bad rear main leak. It has about 285,000 miles on the ticker. That's OK though I have a "fresh" 460 with only 219,000 ready to go in.
Yeah, my 89 F150 is hard on gas too. 89 S/C 4x4 302 AOD. I average between 10-13 combined driving, winter-summer.
Mileage pole 2000 Buick LeSabre w/3800 30 Highway/25 City 1991 S-10 Pickup w/2.5 an 5-Speed 25 Highway AND city. Go figure,lighter and smaller than the LeSabre. 1973 Regal w/ original 455 engine. Mods: 72 Stage 1 heads, B4B, 2 1/2 duals with turbo mufflers. Highway 14 and city 10. Just can't seem to lite foot it! Too much fun.:laugh: Ed :beer
The day that I start checking mileage I will have to buy a Neon !!!!!!ou: " Built for Comfort and Speed ! " :Smarty: What mileage ?o No: :gt:
The last time I checked was driving from Omaha to North Platte, Ne. (my home town, folks still live there) on 2 lane running around 65 I got just under 17. Not to bad for a stock 150,000 350-4, TH350 and 3.08 posi. Do I really want to put in a hot BBB?
MPG my 1998 regal gs - 28 mpg on the highway & 18 mpg city . my 1972 gs 350 - 18 mpg on the highway & 10 around the city . wife's 1999 saturn - at least 35 on the hwy & 20 city . i must say that i do not concern myself with fuel economy . i bought my cars to drive & enjoy !
My 72 GS with a mild 455 (118-Edelbrock intake-Q jet and headers) and a 200-4R pulls 17-18 on the highway. My 37 with almost the same engine but stock exhaust and a 2.56 axle gets 16-17 My 69 Sportwagon with a 350 and Q jet gets 15-16 The 40 convertible with the straight eight gets 16-17 the 63 Electra with a 401 gets 14-15 Mileage does concern me as I put on average10,000 miles or more a year on the old cars.
1970 Skylark 550 cid [stroked cadillac 500], Holly 850 DP, 295* cam, headers, 10.5:1 pistons, ported and polished heads, MSD 7AL box, SP T-400 tranny with 1000/3000 converter, 9 inch ford rear end with 3.70's, tubbed with 15 inch wide Mickey T's. Basically all stock steel body gets exactly 6 MPG..... That's it:Brow: 1970 GS-350 Stock 1969 350 short block, just new rings and bearings, 10.5:1 stock pistons, but decked to bring them up to .020, 290/310 Crower cam. Home ported/polished/port matched 1972 heads and iron intake, HEI distributor with ACCEL goodies, rebuilt stock '70 GS Q-jet fed thru a stock GS air cleaner, but with a Chevelle style cowl induction scoop on a skylark hood, stock iron exhaust manifolds with 2.5 duals, power built T-350 with 2500 converter, 8.5 psi rear-end with 3.91's spinning 275/50/15's [and it will spin them... quite well] 100% stock steel body with full interior, and a nice stereo gets about 10-11 MPG... Not much highway use with the big gears and converter, so I dont know for sureo No:
My `72 (see sig.) got 12.4 mpg last weekend during the trip to farmington drag strip. This included mostly highway driving but several 1/8 mile runs. Highway speed was around 65 mph. Car has 10.5 C.R., 800 cfm Q-Jet, SP-1, ported small valve heads, headers, TH-350 with 2700 stall, 275/60's rear, 235/60 front and 3.42 gears.
