Hi all, New to the board here. Joined up due to that I'm looking at getting a 1967 Riviera (or possibly a 69) and this place seems like a great place to start learning about these cars! One question I have is what kind of MPG can you expect from a 67 Riviera? I realize its no prius in terms of fuel economy, and its not a crucial thing for me. But I also would like to not average less than 10 mpg. Is a number somewhere around 14 or 13 mpg possible with these? Is there anything mild that can be done to improve mpg? I've seen things like a trans/engine swap to a more modern one, etc. but that's too pricey to even consider for me at the moment.. The one I'm looking at has a 430 under the hood. I saw a few threads online about some late 60s Electra's I believe with a 430 in which people had been able to average near 20 mpg, sometimes more. Wondered if this would ring true with Riviera's too? Any info or suggestions would be appreciated, and I'm looking forward to learning from you guys on this board!!
20 mpg with a bbb is a pipe dream. Depending on gearing and driving habits I would think about 11 city and 13-14 highway.
When my 68 was stock with 3:07 gears I got 18 on the hwy 10 - 12 around town. Now its modified and she gets 10-14 hwy and 8-10 in town. If you chose to drive a BBB dont expect fuel economy.
All depend on the condition of the engine, carburetor, distributor, and how well its tuned. I've owned 67s for about 30 years. I've got as much as 17 on the interstate type driving at 65mph with a fresh rebuild after break-in but reality for most cars plan on 12 at best for everyday driving and that's with a light foot on the accelerator. Get into the 4 barrel and it will easily drop into single digits. Don't expect 13-14 normal everyday driving. Not saying it can't be achieved under perfect conditions but its just not reality.
I don't have anything with a BBB, but I've noticed that my fuel mileage in everything I own (with a carb) pretty much stinks anymore. Even my Corvair averages around 18 MPG, and my Dart wagon with a Slant Six pulls maybe 18-19 on the highway. Add any city driving and everything plummets. I've got them reasonably well-tuned with a wideband (but try to keep them tuned for driveability). Modern gas kind of stinks for old cars.
Using 91 octane, I get between 14-16 on the highway...a couple less around town. My 430 is basically stock, with the big-port heads and factory 4MV q-jet (with modern pump gas upgrades and newer rods/jets), and pertronix ignitor III ignition. I did have the engine balanced/blueprinted, and the heads upgraded with bronze guides, new valves and hardened seats for unleaded fuel. The 67 is a nice balance of power/agility...it has the more modern V8 without being as long & heavy as the later year models. I love the rumble of the V8 while cruising around town, and it eats up the miles on the highway. Can't wait for next year's ROA meet in St. Charles...that will be a nice trek.
