Powerglide Posted August 28, 2009 Share Posted August 28, 2009 Just took a 4 tank average. 1976 280Z, Stock EFI, 205 65R 15 tires on 15x7 Konig Rewinds. 93 degree heat in S. Florida, A/C on the entire time. Car has factory 4-speed and the usual R200 diff with 3:54 ratio. Driving is about 60% city 40% highway. I drive it moderately hard... Plenty of down shifting and 80mph runs on the Florida TPK. No effort made to "keep my foot out of it". Mobile Gas 89 Octane with Summer Blend 10% ethanol (hurts MPGs) Results on 4 tanks---17mpg Overall--never worse than 15.5 mpg---city/stop and go ONLY with a/c on. Best ever is 23mpg at 75 to 80MPH with the a/c off in cooler weather, ONLY on the highway. A lighter foot might stretch this a little. But an overdrive would put the car into the mid to high 20s on the expressway. A little MORE COMPRESSION would help a lot too. But the motor only has 159K on it... Quote Link to comment Share on other sites More sharing options...
Daeron Posted August 28, 2009 Share Posted August 28, 2009 Just took a 4 tank average. 1976 280Z, Stock EFI, 205 65R 15 tires on 15x7 Konig Rewinds. 93 degree heat in S. Florida, A/C on the entire time. Car has factory 4-speed and the usual R200 diff with 3:54 ratio. Driving is about 60% city 40% highway. I drive it moderately hard... Plenty of down shifting and 80mph runs on the Florida TPK. No effort made to "keep my foot out of it". Mobile Gas 89 Octane with Summer Blend 10% ethanol (hurts MPGs) Results on 4 tanks---17mpg Overall--never worse than 15.5 mpg---city/stop and go ONLY with a/c on. Best ever is 23mpg at 75 to 80MPH with the a/c off in cooler weather, ONLY on the highway. A lighter foot might stretch this a little. But an overdrive would put the car into the mid to high 20s on the expressway. A little MORE COMPRESSION would help a lot too. But the motor only has 159K on it... So you're tellin me that there is a 76 280 on Konigs running around in Lake Worth??? How the heck have I never seen you? Granted, I usually stick around the north end of town (PBG thru Lantana == "Town" to me; I am an old skool West Palm baby.) Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 28, 2009 Share Posted August 28, 2009 72 240z L28 turbo 5 speed 3.54:1 rear SDS running closed loop at cruise 26mpg highway, 21mpg city Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 28, 2009 Share Posted August 28, 2009 75 Fairlady Z Automatic, 4.11 Gears, stock L24 with triple 40 Mikuini PHH's & Trust/Greddy Exhaust: 28mpg steady at 65mph from Victorville to Phoenix. 74 260Z, Late 5 Speed, 3.7 Gears, Stock L26 with stock exhaust as low as 19mpg from Oglalla NE to Grand Rapids MI in about 10.5 hours (math skills). Same car running through Wisconsin later in the same trip cracked 27mpg when not exceeding 65mph through the entire state. Averaged 24mpg at highway cruise, and 17 in small cities and gravel roads playing WRC. 75 FairladyZ 2/2, 3.9 gears, early 5 Speed, 2.5" Crush Bent Exhaust, towing an 800# trailer at 3200 freeway rpms got consistent 22mpg. Gets roughly the same mileage when cruising at 3500 rpms on the highway with no trailer. Hard to break below 20 in town. Car dynoed at 147rwhp, turned consistent 15.50's in SanAntonio all day long. 73 240Z, 3.7 gears, late 5 speed, Blowthrough 44 Mikuini Triples combined commuter duty at 17mpg. Personal best (?) mileage: 5mpg...on a track, of course. One that winds through Hacienda Heights, it has since been removed I believe...yeah, track... Quote Link to comment Share on other sites More sharing options...
Project Z Posted August 31, 2009 Share Posted August 31, 2009 I wish I knew what my mpg on my Z. The fuel gauge moves around too much! I guess I can calculate with my fill ups and how much I put in and the miles I make. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted September 1, 2009 Share Posted September 1, 2009 Fill ups are really the easiest way to calculate it... Quote Link to comment Share on other sites More sharing options...
Project Z Posted September 1, 2009 Share Posted September 1, 2009 Fill ups are really the easiest way to calculate it... I figured as much since I've searched the forum on how to fix the fuel gauge needle moving around every minute to no avail. I guess the only way is to replace the fuel gauge and the fuel gauge float? (the thing inside the fuel tank) Quote Link to comment Share on other sites More sharing options...
ZWOLF Posted September 1, 2009 Share Posted September 1, 2009 This is sooo NOT my thread! Quote Link to comment Share on other sites More sharing options...
datsun723 Posted September 1, 2009 Share Posted September 1, 2009 1978 280z with 205/70/14 and twice pipes-27 on the freeway keeping it at 70 with the stock 5 speed. Around town....15-20. Depends on how I drive it Quote Link to comment Share on other sites More sharing options...
Rustyfriend Posted September 1, 2009 Share Posted September 1, 2009 With boost and a lead foot....I don't even want to talk about it. Quote Link to comment Share on other sites More sharing options...
Daeron Posted September 1, 2009 Share Posted September 1, 2009 With boost and a lead foot....I don't even want to talk about it. But WE do!! Not to pick on your post in particular, but the idea of being bashful about the MPG of your performance-built vehicle, or not wanting to talk about it has always struck me as odd... It isn't like its something to be ashamed of... Fast cars burn gas, it goes without saying. There is a reason I don't even look at any boat larger than 25 feet... Even a 25 foot Mako with a 150-200 horse on it would drink too much gas for me to "just take it out whenever..." I would need to think about gas money. A 19 footer with a 90-125, on the other hand... HUGE difference. I make that decision when I buy the boat; you make the MPG decision when you build the car. But it is a data point just like any other, and I think that the PURPOSE of this thread is to compare the fuel consumption of Z-cars in EVERY trim, from stock DD, to eco-modded DD, to full blown race. (John Coffey, Greg Ira, Tony, Braap, jmortensen, any other racers want to chime in?) Quote Link to comment Share on other sites More sharing options...
Rustyfriend Posted September 1, 2009 Share Posted September 1, 2009 Alright, I haven't really analyzed the numbers lately but with me always wanting to drive in boost, I say I am averaging about 14mpg driving around town. Not sure about highway yet, because I just got a sweet 81 5-speed in the car and I am using my stock 3.54 r180 Quote Link to comment Share on other sites More sharing options...
Meph Posted September 2, 2009 Share Posted September 2, 2009 Ive got a 1JZ in my car run on an after market ecu, r154 trans with a r200 3.545 2316 RPM @ 100 km/h. Aiming to crack 30 + mpg and 300+ hp Quote Link to comment Share on other sites More sharing options...
Daeron Posted September 2, 2009 Share Posted September 2, 2009 Alright, I haven't really analyzed the numbers lately but with me always wanting to drive in boost, I say I am averaging about 14mpg driving around town. Not sure about highway yet, because I just got a sweet 81 5-speed in the car and I am using my stock 3.54 r180 14 mpg is not all that bad for a hi-po sports car at ALL, I was afraid you would say more like ten. My brother estimated that his ITS car is going to yield about 5-6 mpg, and that blew my mind even though I know it is likely true... Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted September 2, 2009 Share Posted September 2, 2009 Well, after my recent carb re-tune, my wallet sure *feels* like it's getting better MPG, but I guess the real test will be when I drive out to visit my folks in a few weeks. My best ever on that trip (~130-150 miles, depending on the route) was 20mpg. My gut is saying I might be able to do 23ish this next one... Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted September 2, 2009 Share Posted September 2, 2009 14 mpg is not all that bad for a hi-po sports car at ALL, I was afraid you would say more like ten. My brother estimated that his ITS car is going to yield about 5-6 mpg, and that blew my mind even though I know it is likely true... Most cars get 5-10mpg when accelerating. Any car that's driven like a sports car SHOULD get lousy mileage. Fast acceleration requires high power and high power comes from high fuel flow. The MAIN way to get better mileage is to drive very conservatively off the line with very little throttle. Anyone can get 17-20mpg in the city with a light 1st gen Z car with just about any engine under the hood or whatever gears are in back. The "trick" is not demanding power and that means driving like an old lady for the entire time between fill ups. Personally; I did not buy a 1st gen Z car to drive like an old lady. . Quote Link to comment Share on other sites More sharing options...
78Z/250GTO Posted September 12, 2009 Share Posted September 12, 2009 Never bothered to find out. don't care. just cruzzzzzzzzzzzzzzzzzzzzz Quote Link to comment Share on other sites More sharing options...
Vaughn Posted May 2, 2010 Share Posted May 2, 2010 I actually keep track of this on every car i've owned. 1973Z with 280z engine= 22mpg city 26mpg hwy 1974Z stock 15mpgcity 22mpg hwy Friends 1973Z? EFI [i think?] 26mpg city 32mpg hwy. ^^^stock? He's been working on making light and idk what the heck he's done besides that. Car is gutted. Quote Link to comment Share on other sites More sharing options...
Two80z4me Posted May 3, 2010 Share Posted May 3, 2010 You got better mileage in the city than on the highway? yeah, when Im on the highways in montana the car is rarely under 95mph, unless im in a hotspot for highway patrol. In the city, I dont even mess around with driving like an asshat, I save that for track days/auto-x or late night drifting sessions. Quote Link to comment Share on other sites More sharing options...
yetterben Posted May 5, 2010 Share Posted May 5, 2010 73 240z L28 5 speed. Triple weber 40's Blow through turbo. Mid teens at 65. 2-4mpg on boost. Quote Link to comment Share on other sites More sharing options...
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