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What fuel Mileage do you get with your 5th Ave? #1317796 10/09/12 12:36 PM 10/09/12 12:36 PM
Joined: Aug 2006 Posts: 8,064 Iowa 76dodgeboy OP master
76dodgeboy OP master Joined: Aug 2006 Posts: 8,064 Iowa	I posted asking what headers etc will fit a 5th ave. I wanna know what you guys are pulling down for mileage in yours and what your combo is. Also what size tanks do they have? Mine might need a carb swap and leanburn delete already .

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317797 10/09/12 12:56 PM 10/09/12 12:56 PM
Joined: Jun 2009 Posts: 101 South Carolina W warpspeed member
warpspeed member W Joined: Jun 2009 Posts: 101 South Carolina	you need to check out dippy.org. They are the M body pros. Might find out more information there too. I think I only get 15 MPG. I have a highway gear and still can't get good mileage. I am not going back to the lean burn to get better mileage either.

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317798 10/09/12 01:13 PM 10/09/12 01:13 PM
Joined: Dec 2005 Posts: 1,156 Cruising! Q QuickDodge super stock
QuickDodge super stock Q Joined: Dec 2005 Posts: 1,156 Cruising!	The origina EPA estimates were 16 mpg city and 22 highway for a 1985 model year 5th Avenue. The EPA has since revised all of their mileage figures. The new mileage figures are 15 city and 20 highway. It's interesting to compare the 5th Avenue's mileage figures with the 1985 Diplomat POLICE car's mileage. (The civilian and police cars are rated separately) The EPA's original estimates for the police car were: 13 mpg city and 15 mpg highway. The EPA's revised figures are: 11 mpg city and 14 highway. The civilian Diplomat's mileage ratings are identical to the 5th Avenue. So the question is why did the police Diplomat use so much more fuel than the civilian cars?

Re: What fuel Mileage do you get with your 5th Ave? [Re: QuickDodge] #1317799 10/09/12 01:23 PM 10/09/12 01:23 PM
Joined: Feb 2003 Posts: 21,318 Manitoba, Canada DaytonaTurbo Too Many Posts
DaytonaTurbo Too Many Posts Joined: Feb 2003 Posts: 21,318 Manitoba, Canada	In the mid 90's my dad had one with a slant. He said he got low 20's with it on the highway.

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317800 10/09/12 01:44 PM 10/09/12 01:44 PM
Joined: Aug 2005 Posts: 11,543 chicagoland,usa B buildanother I Live Here
buildanother I Live Here B Joined: Aug 2005 Posts: 11,543 chicagoland,usa	Had an 87 in about 1996, it had no gear but got at least 22 highway. With the lockup it was barely spinning the 318 on the road.

Re: What fuel Mileage do you get with your 5th Ave? [Re: buildanother] #1317801 10/09/12 02:46 PM 10/09/12 02:46 PM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	My Mom's 86 would knock down consistant 25s on the highway at 65 - 70 mph. That car had something like a 2.21 rear gear so the low First in the A-998 was a real help. Funny thing, it didn't seem slow. That's the engine I'm building for my '64Dog. After 100K miles, there is virtually no ridge in the cylinders and all the valve seats and guides are usable. Those engines never had to work hard because the two-barrel carb wouldn't let them, along with the blue-haired old lady driving them! R.

Re: What fuel Mileage do you get with your 5th Ave? [Re: QuickDodge] #1317802 10/09/12 05:15 PM 10/09/12 05:15 PM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: The origina EPA estimates were 16 mpg city and 22 highway for a 1985 model year 5th Avenue. The EPA has since revised all of their mileage figures. The new mileage figures are 15 city and 20 highway. It's interesting to compare the 5th Avenue's mileage figures with the 1985 Diplomat POLICE car's mileage. (The civilian and police cars are rated separately) The EPA's original estimates for the police car were: 13 mpg city and 15 mpg highway. The EPA's revised figures are: 11 mpg city and 14 highway. The civilian Diplomat's mileage ratings are identical to the 5th Avenue. So the question is why did the police Diplomat use so much more fuel than the civilian cars? they have an 18 gallon tank. dippy cop cars had a 360 top end (heads, intake, and 4bbl carb) the 2.21 rear gear kills mileage in town...I could usually get 13 in town stock. best I ever got was 25mpg going to detroit and back, and that was with the cruise set near 80mph. set the cruise at 65-70 and mileage was about 23. that was stock. mixed driving was pretty consistant at 18mpg....once I modded for power, mileage went down, even with the A500 OD tranny. never took it on a full highway trip in it's last incarnation (mag headed 318 roller cam motor, A500, 3.55 rear gears), but it was very consistent at 17.5mpg in mixed driving, so it probably could've knocked down 22-23 all highway, and probably could have been even better with a t-quad or one of the new street demon t-quad clones over the 600 eddie AFB I had....a FAST EZ_EFI would have been neat to try, too... that said, my '11 charger R/T is faster, more comfortable, and handles better, and for the 8k miles I've owned it, the same commute I averaged my rock steady 17.5mpg in the modded 5th, I'm averaging 23mpg... a 5.7/A580 would be sweet in one if you could pick one up cheap enough. would require significant mods to fit the tranny in. a 5.7/A833OD would also be a fun combo, coupled with a 3.23 rear, and would probably knock down 25mpg highway.... 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: What fuel Mileage do you get with your 5th Ave? [Re: dogdays] #1317803 10/09/12 05:21 PM 10/09/12 05:21 PM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: My Mom's 86 would knock down consistant 25s on the highway at 65 - 70 mph. That car had something like a 2.21 rear gear so the low First in the A-998 was a real help. Funny thing, it didn't seem slow. That's the engine I'm building for my '64Dog. After 100K miles, there is virtually no ridge in the cylinders and all the valve seats and guides are usable. Those engines never had to work hard because the two-barrel carb wouldn't let them, along with the blue-haired old lady driving them! R. I THINK they came from the factory with moly rings...or the blocks have A LOT of nickel in them. what heads are you going to use? the stock 302's? send your roller cam off to bullet cams to get reground. have them put their HR259/326 lobe on the intake and their HR266/325 lobe on the exhaust. it'll wake things up significantly while still having nice road manners and economy. if the roller lifters are in good shape you can reuse them. you may need to buy longer pushrods (or get the heads milled a little bit) and you'll want to swap springs with some hughes #1110's.... 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: What fuel Mileage do you get with your 5th Ave? [Re: patrick] #1317804 10/09/12 06:07 PM 10/09/12 06:07 PM
Joined: Aug 2006 Posts: 8,064 Iowa 76dodgeboy OP master
76dodgeboy OP master Joined: Aug 2006 Posts: 8,064 Iowa	The car will see 75-85% highway use as we live about 30 miles from work and I29 is the route to work. Would the 195s eat more gas than the stock 205 size thats suppose to be on it?Its at 113 miles from when I picked it up with a full tank and seems to be an 1/8 above have tank So my guess is currently around 14mpg. Pretty sure carb needs a rebuild and possible bad gas that was aparent after I got it home. Ran pretty good down the interstate. Is there a diff between car and truck 4bbl kickdown linkage? I have a few truck ones

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317805 10/10/12 01:50 PM 10/10/12 01:50 PM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	well, 195/75R15's are 1/2" shorter than the stock 205/75R15's...it's 2% difference. so....if 75mph was 2000 RPM with the stock tires, it would be 2040RPM. negligible difference. assuming a dead-nuts speedo and odo with stock tires, 60mph indicated would actually be 58.9mph. 100 miles indicated driven would actually be 98. so it would skew your gas mileage calculations the other way (overestimating miles driven). don't trust the gas gage. on my 5th ave with the 360 in it, it would go 150 miles to 1/2 tank, and be near E and the low fuel light would come on at 225-240 miles, and take about 15-16 gallons to get to full. with the mag headed 318, I typically got 280 miles before the low fuel light, and it would take about 16 gallons to fill, with 180 miles on the trip odometer at 1/2 tank... 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: What fuel Mileage do you get with your 5th Ave? [Re: patrick] #1317806 10/10/12 10:10 PM 10/10/12 10:10 PM
Joined: Jan 2003 Posts: 3,472 Lubbock, TX E Erics5th UsedtobeSatellite6
Erics5th UsedtobeSatellite6 E Joined: Jan 2003 Posts: 3,472 Lubbock, TX	How my 5th is set up: 318, Performer intake/1406 carb, HEI ignition, lock up trans with a Superior TF-TC shift kit (mainly to raise the lockup speed), 8 3/4 rear with 2.94 gears and 215/70R-15 tires. When I did a daily 80 mile round trip commute, it would usually get around 22 MPG at 65, a little less at 70. Eric

Re: What fuel Mileage do you get with your 5th Ave? [Re: Erics5th] #1317807 10/10/12 10:58 PM 10/10/12 10:58 PM
Joined: Aug 2006 Posts: 8,064 Iowa 76dodgeboy OP master
76dodgeboy OP master Joined: Aug 2006 Posts: 8,064 Iowa	Might have done better with a 500cfm. Im shooting for 25mpg

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317808 10/10/12 11:22 PM 10/10/12 11:22 PM
Joined: Jan 2008 Posts: 4,255 Canada WO23Coronet master
WO23Coronet master Joined: Jan 2008 Posts: 4,255 Canada	My parents had an 82 and an 86 in the early 90's, on the highway (95% of the driving) they got 22-24 mpg, stone stock nothing done to them at all, running 205/75/15's. And they had those ridiculous 2.21 or 2.45 gear sets. My brother had an 82 Cordoba with a low mile 1990 318 in it with a thermoquad, MP 430/450 260/268 cam and dual exhaust. With a 2.94 8.25 diff he also got low 20's on the highway. Pretty zip to, would beat a 5.9 Durango R/T in a street race.

Re: What fuel Mileage do you get with your 5th Ave? [Re: WO23Coronet] #1317809 10/10/12 11:34 PM 10/10/12 11:34 PM
Joined: Aug 2006 Posts: 8,064 Iowa 76dodgeboy OP master
76dodgeboy OP master Joined: Aug 2006 Posts: 8,064 Iowa	Well if I hit 25 I'll up my goal to 28-30

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317810 10/11/12 08:49 AM 10/11/12 08:49 AM
Joined: Jan 2003 Posts: 3,472 Lubbock, TX E Erics5th UsedtobeSatellite6
Erics5th UsedtobeSatellite6 E Joined: Jan 2003 Posts: 3,472 Lubbock, TX	When I first bought my 5th, my friend that I bought it from had an old Edelbrock SP2P 4bbl manifold on it and a Holley 4360 450cfm (an economy replacement for Quadrajets) on it. It did about the same for milage. Had great low end torque with the small runners though. Eric

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317811 10/11/12 02:23 PM 10/11/12 02:23 PM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: Might have done better with a 500cfm. Im shooting for 25mpg then stay away from the AFB/squarebore carbs and go for a T-quad/q-jet or the new street demon. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: What fuel Mileage do you get with your 5th Ave? [Re: patrick] #1317812 10/11/12 05:38 PM 10/11/12 05:38 PM
Joined: Aug 2006 Posts: 8,064 Iowa 76dodgeboy OP master
76dodgeboy OP master Joined: Aug 2006 Posts: 8,064 Iowa	Why?

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317813 10/11/12 05:57 PM 10/11/12 05:57 PM
Joined: May 2003 Posts: 15,487 Florida S scratchnfotraction I Live Here
scratchnfotraction I Live Here S Joined: May 2003 Posts: 15,487 Florida	the primary triple venturie on a spredbore is why a q-jet/thermobog do so well on the mpg. small primarys for great throttle responce,triple venturies do better at atomizing the fuel into the air mix. very tunable with 3 step needles and jets(eddies are 2 step needles) when you are on the 2ndarys there is no consern with mpg. it is all about the s**t and get. work on everything from a 273 to a 440 for street duty and mild performance. not to mention they sound kool when they open up and dont have any bogs to them. I can stomp my 318 with q-jet from a 650 rpm idle to a full WOT run with no bogs,gets 19+ mpgs in the truck if i drive like "Ma & Paw kettle" cant wait to get the q-jet from the 454 chebby set up for the 440 truck myself. I am shooting for anything over 10 mpg with it. stock 440,q-jet,3.23 should do a little better than the eddy 600cfm with 3.91 gear. I am just glad I get 19+ with the 85 truck as a daily drive 80 miles perday round trip.

Re: What fuel Mileage do you get with your 5th Ave? [Re: scratchnfotraction] #1317814 10/11/12 08:09 PM 10/11/12 08:09 PM
Joined: Aug 2006 Posts: 8,064 Iowa 76dodgeboy OP master
76dodgeboy OP master Joined: Aug 2006 Posts: 8,064 Iowa	I have a stock 4bbl carb from an 85 360. That a thermoquad and would that work or is it to big?

Re: What fuel Mileage do you get with your 5th Ave? [Re: 76dodgeboy] #1317815 10/11/12 09:12 PM 10/11/12 09:12 PM
Joined: May 2003 Posts: 15,487 Florida S scratchnfotraction I Live Here
scratchnfotraction I Live Here S Joined: May 2003 Posts: 15,487 Florida	may need tuning/rejetted but would work as it is a SB thermobog. it will have the smaller primary bores compaired to larger primary bores of a BB thermobog. may need the same tuning with any q-jet or other carbs brands as well,if you want the most from it. I use a chebby 327 q-jet on my 318,very close on jetting and tuning. the q-jet from the 454 should be in the ballpark for the stock 440. dial them right in with a vac gauge and get the 2ndary airdoor adjusted just right and no bog on the transition tip in. and the q-jet is cheap to rebuild and mod o fry. if you stay with a chebby carb the fuel inlet is to the side,the GM/GMC/pontiacs are front feed and can interfear with the rad hose/t-stat location. you can get the short q-jet inverted flare fitting and ditch the filter to shorten it up some. grind the chebby throttle lever off and tac a mopar q-jet lever on and all the stock linkage works with the early non emissions chebby q-jets with looking for a carb. the carbs that have 704** as the first 3 digets in the # are the bestest...ones with 1704* or next bestest when junkyarding for them. if you know how and can fine tune a thermobog it may out do the q-jet. q-jet areless work tuning. i dont get the how to on thremobogs

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