Early Ford V-8 Club Forum

EFV-8 Club Forum / General Ford Discussion / gasoline mileage, 21 stud V-8

Reply to Discussion | New Discussion << previous || next >>

Posted By Discussion Topic: gasoline mileage, 21 stud V-8     pfrancis 08-26-2010 @ 10:58 PM reply profile send p.m. Member Posts: 27 Joined: Oct 2009 I am getting about 13 mpg on the road on a new engine in my 35 fordor touring sedan. Engine is running fine. I am wondering if this is about normal. I had hoped for better mileage. What are others getting? Thanks for inputs, pfrancis 37RAGTOPMAN 08-27-2010 @ 6:51 AM reply profile send p.m. Senior Posts: 1959 Joined: Oct 2009 how many miles on the engine,, you have to remember the engine is still maybe breaking in, also what rear end ratio do you have,???? this has a lot to do with how much miliage to the gallon you will get, pull a spark plug and see what color is it? black running too rich,[ jets in carb to big? } should be a light tan color.this is ideal make sure the choke is all the way off,also check the choke rod, you can bend to make sure it is all the way off. also check the brakes, and hand brake there is no drag, hope this helps, 37RAGTOPMAN an KEEP ON TRUCKIN,,, TomO 08-27-2010 @ 7:01 AM reply profile send p.m. Senior Posts: 7252 Joined: Oct 2009 How fast are you driving? The 35 ford is not very aerodynamic and at speeds above 40 mph the wind resistance is very high. Mileage depends upon several conditions, the engine condition being only one of them. Some more areas that can affect mileage are: tire inflation, alignment, driver, brakes and differential ratio. Tom keith oh 08-27-2010 @ 7:05 AM reply profile send p.m. New Member Posts: 116 Joined: May 2010 That is not much out of line as about 15-17 MPG is about average. Most 35s came out with a 4:11 rear end ratio which is very low and unless it has been changed is probably what yours is. You can run 650X16 tires on the rear insted of 600X16 and run at least 35 lbs pressure.Make sure your choke plate is wide open and the Air cleaner is clean as any little obstruction will lower mileage. Set the vacuum advance to just where the pre ignition ping stops. Last but not least, I guess the old saying " If you can't stand the heat in the kitchen then get out" applies. (Grin) supereal 08-27-2010 @ 11:31 AM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 Be sure that your speedometer drive gear is correct for the rear end gearing, and that you are using the original tire size, probably 600X16. More often than not, anyone with very low gas mileage probably has a mismatch between the speedometer and the driven gear because the rear end was changed at some time. The number on top of the "turtle" (gear housing on the torque tube just behind the transmission), should tell you what it is. If you know your rear end ratio, we can tell you what number of speedo gear teeth is correct. The common MPG for overall driving of an old Ford falls in the 14-16 range with careful driving. Being off just one tooth can make a big difference. pfrancis 08-27-2010 @ 10:21 PM reply profile send p.m. Member Posts: 27 Joined: Oct 2009 Yes, I have a 4:11 rear end, and have no O.D. Speedometer and odometer are accurate. Maybe my mileage will improve when I get more miles on the engine. Now I have about 1000 miles. I got 13 mpg driving 55 on mountain roads. Thanks for the answers, pfrancis supereal 08-28-2010 @ 5:10 AM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 With that rear end, and mountain roads, that is not a bad MPG. With an OD in my '47, out here in "flatland", I manage about 14-15. These old cars were built in an era of 25 cent a gallon gas, so there wasn't much attention paid to efficiency. 37RAGTOPMAN 08-28-2010 @ 5:52 AM reply profile send p.m. Senior Posts: 1959 Joined: Oct 2009 If you were to replace the rear end gears with a 355-1 your gas miliage would increase,RPM'S GO DOWN, would be better on the open road, then in the mountains,but still climbs hills, just not with the power it had before,you just have to increase the speed before you reach the hill, I installed a 354-1 ratio about 4 years ago, and the car runs so much better, CUTS THE RPM in the engine,this in a 37 Cabriolet 85hp car, does 60 with no problems,and can do more, but I, keep it around 55-60. less strain on the engine,for sure. WOULD NEVER GO BACK TO THE 378-1 for SURE. if you were to have a ride in a car with the 354 gears you would see how much better it is, especially if you plan on using the car on tours with your local club,you will get more use out of your car, hope this helps, 37RAGTOPMAN an KEEP ON TRUCKIN,,,,!! I also believe that dual exhausts make it run better,,, TomO 08-28-2010 @ 7:37 AM reply profile send p.m. Senior Posts: 7252 Joined: Oct 2009 If you are driving a lot on mountain roads, I would not put a 3.54:1 rear end in the car. Your mileage will suffer do to the downshifting required to maintain speed. A 3.78:1 would help some, maybe give you another mile or 2 per gallon, but at an average of 3000 miles a year for a collector car, it would take many years to recover the cost. If I keep the speed below 50mph in my 40 with a 3.54:1 and 6.50x16 tires, I can get about 18 mpg. At 55-60 it will drop to the 14-16 mpg. Tom 1934 Ford 08-28-2010 @ 5:37 PM reply profile send p.m. Senior Posts: 573 Joined: Oct 2009 We get 15-18 depending on speed and road conditions with 4 adults in the car (Non called Twiggy either). We do lots of National Tours and local tours and find anyhing from 53 MPH down to be economical and enjoyable even with the 4:11 rearend. If we plan an Interstate Highway trip, we put it on a trailer and haul it to the Two Lane Road Tours. We beleive these cars were built for two lane roads and feel fortunate to find much better two lanes in 2010 than could be found anywhere in 1934. We own the car to drive it. We feel that seeing America on two lane roads is a perfect match for the machine and our wanderlust and love of old flathead Ford V8's. We can get it up to 70 plus MPH to pass, but it hums at 53 MPH and gets 18 MPG.

<< previous || next >>

NOTE: YOU MUST BE A REGISTERED USER AND BE LOGGED IN TO POST (and reply to) messages in this forum. If you are a first time user, please click the CREATE A NEW ACCOUNT in the masthead above to register and Log In. After that, all you do is LOG IN to enjoy using this site.

DISCLAIMER: The V-8 Club does no independent testing of any of the opinions, thoughts or suggestions presented in the website on the Forum, in the Tech Tips section, or any section. A reader should consider the website to be a forum wherein differing solutions to a particular set of circumstances may be discussed. Ultimately, the selection of an item for an individual's vehicle must be based upon the independent study of the vehicle owner in consultation with people in the hobby and restoration experts.

EFV-8 Club Forum Home | Back to Home Page | Contact the Webmaster

Copyright © 2009 - EFV-8.org
Powered by < CF FORUM > v.2.1