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| | | | Joined: Jan 2015 Posts: 22 'Bolter | | 'Bolter Joined: Jan 2015 Posts: 22 | I’m nearly getting to the point with my 49 Suburban project where I will be able to drive it
With the following specs is anyone able to take a shot at what Mpg it might return on the highway running at 70mph?
1949 Suburban
Stovebolt 261
Twin Carter W1 carbs
700r4 Box
Eaton H035 rear axle
Offenhauser intake
Fenton headers
6.50 16 Firestone
49 Suburban Project
| | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | What's the rear axle ratio? | | | | | Joined: Apr 2005 Posts: 7,440 Bolter | | Bolter Joined: Apr 2005 Posts: 7,440 |
Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
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USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
| | | | | Joined: Oct 2006 Posts: 843 Shop Shark | | Shop Shark Joined: Oct 2006 Posts: 843 | | | | | | Joined: Mar 2010 Posts: 10,270 Renaissance Man | | Renaissance Man Joined: Mar 2010 Posts: 10,270 | At 70 MPH you will be impeded by aerodynamics. I doubt that you will get over 15 MPG.
Tire diameter and rear end gear ratio needs to be taken into consideration as well.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | I have often obtained 18 mpg on an Interstate (55-60 mph) - 3.55 rear and 31.5" radial tires.
It drops to 15 mpg (or, less) above 60 mph. | | | | | Joined: Apr 2005 Posts: 2,832 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 2,832 | The HO35 means nothing to me other than it would make a good password. A rear gear RATIO would mean a lot. I think my 37 Buick might be a good comparison as it has a 263ci engine, overdrive automatic, 4.11 gear, and 29" tall tires. The final drive in OD is 2.88---the same final drive most all overdrive vehicles had for years. I removed the sun visor, outside mirrors, and used 215 (narrow) radial tires inflated to 40psi. This bumped me to 16.5 mpg on a 3000 mile trip compared to the 12 mpg with the stock factory set up. A lot of work for not very satisfying results when one considers we put an LS3 engine in a customers 52 Suburban that clicks off 22-23 mpg and can melt the tires.
Evan
| | | | | Joined: Feb 2000 Posts: 5,193 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,193 | I will go with 14 to 16, the wind will kill it. If geared wrong, the overdrive will also kill any mileage. That engine should run in the 2300 to 2500 rpm range for decent mileage. It doesn't have the torque to pull 70 mph at a lower rpm like new, modern engines do. | | | | | Joined: Dec 2002 Posts: 3,437 Moderator - The Electrical Bay | | Moderator - The Electrical Bay Joined: Dec 2002 Posts: 3,437 |
Another quality post.
Real Trucks Rattle
HELP! The Paranoids are after me!
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