Dennis_MN Posted June 5, 2007 Report Posted June 5, 2007 I did a test to see how much fuel my Pilothouse drank. I filled it up on Friday and put on about 122 miles. I used my GPS for to measure my speed and my distance. Filled up again this morning with 8 Gallons and that gives me 15.4 miles per gallon. The fuel that I used is called non-oxygenated because it doesnt contain any ethonal. In Minnesota most gas sold has 10% of the corn juice in it which lowers the mileage a tad. My Ranger can burn E-85 which is 85% and that lowers the mileage from 16mpg to 14mpg. I only use that stuff when the price difference is over 25 cents a gallon. I kept my speed at around 50 to 55 so I was pleased with the mileage. Dennis Quote
Merle Coggins Posted June 5, 2007 Report Posted June 5, 2007 I jealous that you can even do a test like that. I can't wait to be able to drive mine around. Got a bit of work to do yet. Keep it up, Merle Quote
greg g Posted June 5, 2007 Report Posted June 5, 2007 Just as a bit of comparison, I have a P15 Business coupe with a recent engine swap. It originally had a 218 with about 80,000 miles with the stock carter B1B. It generally got 16/17 mpg. this with bias ply tires. I swapped in a rebuilt 230 (.030 over, and 40 of the head 10 off the block) fenton intake with two George Asche B1B's, and radials. On a trip from NY to Vermont summer before last, it got 19 mpg on several tanks full, this on radial tires. Not gps certified but I am pleased by the increase. Would like to hit the 20 benchmark but with the 4.11 rear end I don't think this will happen. Quote
stevenelle Posted June 9, 2007 Report Posted June 9, 2007 My B1B gets about 10 mpg. Bias ply tires; Recent rebuild on 218; City driving with short trips. Is there any hope to getting a boost in mileage. Any suggestions (other than the dual carbs and increased compression techniques. Fortunatley, I only drive it about 150 miles per month, but even then I feel guilty burning so much fossil fuel. Quote
grey beard Posted June 9, 2007 Report Posted June 9, 2007 Greg, What size/diameter radials are you using? My new ones are 215x85-16, and are 31 inches tall. I am not yet on the road - almost, but I'm hoping larger diameter tires will boost mpg, since the crank rpms will be a few hundred lower than with 600 rubber. Your fuel mileage is quite respectable. I would like a chance at using an old Sun distributor test bench to dial in my vac and centrifugal advance curves - something few address. I know it can be done with an advance timing light - just haven't taken the time yet, but I feel sure the real secret to great fuel mileage is in this area. Has anyone done testing on this issue? Thanks Quote
grey beard Posted June 9, 2007 Report Posted June 9, 2007 Dennis, I noted on the other side that you have the same size tires that I just purchased. How are you satisfied with them? How do they affect top highway speed and engine rpm? Can you travel comfortably at 55 mph? I am assuming your rear is also 4:10 like most of us have. Tell us how this size tire feels on a PIlothouse. Thanks Quote
greg g Posted June 9, 2007 Report Posted June 9, 2007 Dave I am running 205 75 r 15's. I beleive they are about 27 1/2 in diameter. I think I should have gone with 215's or 225's being a bit taller. I am running a distributor from a 54 truck. I had it checked on a Sun Machine and it checked out to spec on both mechanical and vacuum advance curves. I believe the higher compression is a big part of the gain. Harder you squeeze it the bigger the bang. I do run about 5 degrees before as my idle setting. I have read from several sources that today's gas has a much slower flame front than the gas of days gone by so the slight advance increase adjusts for the whooomph rather than the blam. Quote
Dennis_MN Posted June 9, 2007 Author Report Posted June 9, 2007 Dennis,I noted on the other side that you have the same size tires that I just purchased. How are you satisfied with them? How do they affect top highway speed and engine rpm? Can you travel comfortably at 55 mph? I am assuming your rear is also 4:10 like most of us have. Tell us how this size tire feels on a PIlothouse. Thanks Yep, tires work good, ride is comfortable, and while I don't have a tach, the engine purrs right along at 55. I caught myself at 60 a couple of times. The only thing that I don't like is that my truck speedodometer and odometer are off because of the larger diameter. I was trying to correct that with a smaller dia tire but they wouldn't work on my narrow rims. I had to use my GPS to measure speed and miles to accuratly measure my miles per gallon. I haven't measured how far off the odometer is off but my speed shows around 10 or so less than actual. Dennis Quote
grey beard Posted June 10, 2007 Report Posted June 10, 2007 Dennis, I will have the same problem with my truck. Anyone on the forum have any experience changing speedo gears? My other thought is that perhaps speedo adaptors from larger trucks - ones that have interchangeable gears like we used to use thirty years ago - are still available anywhere except junk yards. I'm open to suggestions on this one. Quote
Tony_Urwin Posted June 10, 2007 Report Posted June 10, 2007 Call George Asche in Venus, Pennsylvania. You have probably seen posts from P-15 guys who have bought his dual intakes and exhaust manifolds, etc. He rebuilds the overdrive transmissions and can supply you with the appropriate speedo gears. his number is (814) 354-2621. Really an interesting guy. Quote
Young Ed Posted June 11, 2007 Report Posted June 11, 2007 I changed the speedo gear in my coupe to match the 3.73 diff I installed. Wasn't too bad a job but I had the removable floor piece out. My truck reads slow too but its got tall tires and a speedo needle that fell off and was reinstalled my me. And Dave Napa still has those little gear boxes. Dads R110 IHC needs one and they said they could make it up anytime. Not sure what all you need to know to get the gearing right or if you just have to keep trying until you get it right. Quote
John-T-53 Posted January 22, 2012 Report Posted January 22, 2012 (edited) Bringing this one back up top. On the subject of gas mileage, I'm getting 13 around town and anywhere from 15 to 19 on the highway. Not too bad (all things considered). This is with the T5 OD trans, but running a single barrel carb and everything else stock. What's the prevailing opinion on mileage/performance improvements by upgrading to a dual one barrel setup? I think this would be a cool project, and apparently I have the right cyl head (the P head w/ bolt hole for linkage). Thanks, Edited January 23, 2012 by John-T-53 Quote
pflaming Posted January 22, 2012 Report Posted January 22, 2012 Dennis: (1) which engine, (2) tranny, (3) differential ratio, (4) tire size. I think I know 3 or the 4 but would like to see all in one post. Thank you. Quote
Dennis_MN Posted January 22, 2012 Author Report Posted January 22, 2012 (edited) Dennis: (1) which engine, (2) tranny, (3) differential ratio, (4) tire size. I think I know 3 or the 4 but would like to see all in one post. Thank you. Back then: engine is 217 stock 6, trannie is 4 speed non-syncro, diff ratio was 4:11, tires are radial 215/85/16R LT Now or last summer, the only change was rear end ratio was changed to 3:73 And mileage on a 600 mile trip was 16.8 at 60 mph. Edited January 22, 2012 by Dennis_MN Quote
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