What's Your MPG?

[Hellion]

I know most of us could care less about MPG (myself included), but a friend asked me what mine was for "Rosie" and I determined she was getting slightly under 14 per gallon. So...with gas prices being what they are now, and going up even further as summer approaches, do you know what's your ride's MPG is???

[Rsnake]

i get 25+ with a gen 3 coyote in a type 65 which is really aerodynamic.
Cannot complain but gas is approaching 7 dollars a gallon in Kalifornia

[BEAR-AvHistory]

Gen 1 Coyote mid 20's.

[Hellion]

Holy cow - 25+? Very nice! :cool:

Here in Fabulous Las Vegas it's now over $6.00 a gallon at Costco for premium unleaded.

[Fman]

I’m right around 13-14 around town if I drive mellow. Have never tracked on freeway (don’t drive on freeway much). Just paid $6.69/gallon for premium the other day in Nor Cal Commifornia. Let us hope there $8/gallon predictions will not actually happen. I can really tell a difference in the air quality here with the “summer blend” they claim to sell us :p

[Cobradavid]

I get about 18 mpg. 4.6L SOHC Modular motor/T3650 5 speed, 3.27 rear gear.

In my corner of the glorious state of Texas (where everyone owns an oil well, right?), gas is $4.10.

[ggunter]

I usually get between 17-18 with a 347 and 3:55 gears. Of course that's easy cruise.

[Fixit]

Low 20's with a Gen2 Coyote & TKO600 (.82 OD), 3:15's out back.

[skidd]

I average 15mpg around town.
And 15/32s of tire wear too!! ;)

[Papa]

Here are some stats from the app I use.

My engine is a 347 with Holley Sniper ... 3.55 gears.

https://thefactoryfiveforum.com/attachment.php?attachmentid=167188&d=1653343084

[Tom Veale]

I just checked my '33 and it's getting 17.1 MPG with a mix of driving and cold starts. I'm hoping for ~20 mpg on the Hot Rod Power Tour next month.
That is with a 5.0L SBF with fuel injection, 3.55:1 rear gears. I roll along at around 65 to 70 at 2000 rpm.
Tom

[TMartinLVNV]

On trips, if I keep it at 65 mph, I have gotten 21 mpg a few times. Typically, I get 18-19. Not bad at all for a 347 SBF with Holley Sniper.

[wallace18]

In my MK4 with a 347, I got 22 highway and 14 fooling around.

https://thefactoryfiveforum.com/showthread.php?19828-Wallace18-quot-s-MK4-Build-Thread

[Alan_C]

Before selling my MK4, as I remember, about 25 Hwy and 17 around town. 2004 4.6L DOHC, TR3650, 3.55 gears with 10.5x 17 rear wheels and 295/35/17 Kumho XS tires.
The beauty of a modern computer controlled FI motor. I see the Coyotes are every bit or more fugal with their consumption. I sure would like to know that mileage a stack injected Coyote gets?
I am hoping for similar mileage with my 2nd Gen Coyote in a 70 Mustang restomod as it will be a bit lighter that the Mustang GT rated at 24/15 but certainly heavier than a MK4.

[bobl]

500 HP/347 with 8 stack. 3.55 gears got consistent 16 mpg back roads driving, 18ish what little highway I've ever driven on. Changed to 4.10 gears and lost about 1 mpg but well worth the change. But, it gets 100 SPG (smiles per gallon)

Bob

[cobrajj]

21 mpg doing a lot of freeway miles. 17 mpg backroads and spirited driving. Stock rebuilt 5.0 HO Mustang drivetrain, , with Ford EFI, 3.55 final drive, 2200 RPM at 70.

[Dave Tabor]

10.5 mpg average over 120 miles at ~3750 rpm.

Dave
Gen III Coupe #17
Carbureted FRPP 302, TKO600 (0.82 5th) 3.55 IRS

[GTBradley]

My best for a tank was 24 in easy mountain driving. It goes down to 22/23 if I’m on the interstate at 83mph. Last tank was 20mpg with mixed driving and an autocross thrown in. Seriously heavy footedness has never gone below 17.

[Jeff Kleiner]

Mildly built EFI 5.0 with Twisted Wedge heads, Stage 1 cam, Track Heat intake, 24# injectors, etc. through 3.55 gears. I'll run 15-16 in town or backroad cruising, 22-23 @ 75MPH on the highway and <7 on the track.

Jeff

[JDFinley]

My Mk3.1 with mildly built EFI 302 is normally low to mid 20's with mild driving.

[john42]

Same as others above. 15ish on average for the casual side road drives that I tend to do. Highway in 5th gear @ 70 can get 25ish. Racetrack... is LOL wut.

[steno]

On my return from San Marcos to Chicago I averaged about 23-24 in my warmed-over 302.

[GoDadGo]

I have no idea; however, I can really go the distance when I'm on the Interstate.
At 70 MPH the Redbone Roadster is lugging a bit at 1,700 RPM.
At 82 MPH the car is much happier turning 2,000 RPM.
It's the only time I can use 6th gear.

1. 383 Small Block SHP Dart (SBC) 10-1 Somewhat Pump Gas Friendly Compression Ratio!
2. Eagle Internally Balanced Rotating Assembly With 6" H-Beam Rods With Floating Forged Flat Tops.
3. Dart Iron Eagle High Port 215 CC Heads with 2.05 Intake & 1.60 Exhaust Valves.
4. Harland Sharp Roller Rockers & Other Go Fast Goodies.
5. Comp Cam Extreme Energy 288 Hydraulic Roller Tappet Cam
6. Edelbrock AVS 800 Feeding A Weiand 7530 Team-G Single Plane Manifold.
7. Schoenfeld IMCA Modified Headers & They Really, Really Fit, But Stuff Had To Move A Bit!
8. New Old Stock Corvette ZF 6-Speed Transmission With Hydraulic Clutch. (.75 and .50 Overdrives)
9. Standard Front End Set Up With Ford Mustang GT Brakes & Forte’s .75” Sway Bar.
10. Standard 3-Link Moser Dana 44 (TSD 500) Rear With 3.73 Gears & Ford Explorer SUV Brakes.

We try to plan all road trips with an Interstate ride to get home once we are done playing.

[boat737]

Looks like I'm tied with Dave for First place (lower is better, right?) 10 1/2, once in a while 11 mpg (consistent over the last 3 years). 99% city driving. 427 Dart, 750cfm Carb, TKO (.82 OD), 3.50 Ford 9 inch.

Being such a light car, I thought it would be better than that, but It's perfect as it is.

[Al_C]

I have no idea; however, I can really go the distance when I'm on the Interstate.
At 70 MPH the Redbone Roadster is lugging a bit at 1,700 RPM.
At 82 MPH the car is much happier turning 2,000 RPM.
It's the only time I can use 6th gear.

1. 383 Small Block SHP Dart (SBC) 10-1 Somewhat Pump Gas Friendly Compression Ratio!
2. Eagle Internally Balanced Rotating Assembly With 6" H-Beam Rods With Floating Forged Flat Tops.
3. Dart Iron Eagle High Port 215 CC Heads with 2.05 Intake & 1.60 Exhaust Valves.
4. Harland Sharp Roller Rockers & Other Go Fast Goodies.
5. Comp Cam Extreme Energy 288 Hydraulic Roller Tappet Cam
6. Edelbrock AVS 800 Feeding A Weiand 7530 Team-G Single Plane Manifold.
7. Schoenfeld IMCA Modified Headers & They Really, Really Fit, But Stuff Had To Move A Bit!
8. New Old Stock Corvette ZF 6-Speed Transmission With Hydraulic Clutch. (.75 and .50 Overdrives)
9. Standard Front End Set Up With Ford Mustang GT Brakes & Forte’s .75” Sway Bar.
10. Standard 3-Link Moser Dana 44 (TSD 500) Rear With 3.73 Gears & Ford Explorer SUV Brakes.

We try to plan all road trips with an Interstate ride to get home once we are done playing.

OK, GoDad, you have 3.73 gears in the rear end, and a .75 and .50 overdrive. You're turning 1700 rpm at 70. Wow. That has to be 6th gear. To keep in line with this thread, if you are lugging the engine, does that have an adverse effect on mileage?

(btw - I have no idea what my mileage is. When it gets low I complain about the price of gas and fill it up anyway)

[GoDadGo]

OK, GoDad, you have 3.73 gears in the rear end, and a .75 and .50 overdrive. You're turning 1700 rpm at 70. Wow. That has to be 6th gear. To keep in line with this thread, if you are lugging the engine, does that have an adverse effect on mileage?

(btw - I have no idea what my mileage is. When it gets low I complain about the price of gas and fill it up anyway)

Like you I have no idea what my mileage is, but when go off cruising and hit the 1/2 tank point we always head for home and fill up our local station (Redfish Fuel) where we can get 93 Octane with no ethanol. I've made it from Biloxi back to Slidell (70-75 miles) and still had a tad more than a 1/4 of a tank of fuel left when we filled up.

When we're not on the interstate the car sucks down fuel like I suck down Tequila, Scotch, or my favorite beverage which is Sazerac Rye.

[john42]

The only thing a Cobra can't pass is a gas station. :-)

[RoadRacer]

I drive my 33 as my daily, and it's driven pretty hard, so I average 11.5mpg from the carb'd SBC

[MikeD]

Back before covid when I was driving into the office, I would regularly see 11.5 MPG.
One time Phil and I took our cars on a highway trip to Black River Falls Wisconsin and I recorded 18.5.

I've got a 351W with holley 750 double pumper, a tremec 3550 5 speed, and 3.27 rear gears.

[Tom Veale]

Back when mileage really sucked - in the 1970s - I created a series of formulas that would help when looking at new cars and the optimistic EPA estimates of fuel economy. I took a stack of Road & Track Magazines and went through their road tests and calculated "worst" and "Highway" mileages and then compared them to the Mag's experience with the cars. It worked pretty well.

It's based in displacement in CCs and RPM at 60 MPH. I did this for both carbureted and fuel injected cars because there was a difference that could be measured. Here are the formulae for the calculation of "Worst" mileage:

For carbureted cars - Worst Mileage
73400000 / (Displacement in CCs X RPMs at 60 MPH)

The calculate value would be multiplied by a factor to bring it to either "average" or "best." For "best" I believe I used 2.4 as the multiplier and for average I used 2.0.

For Fuel Injected cars - Worst Mileage
82670000 / (Displacement in CCs X RPMs at 60 MPH)

Example 1: In the Carb example, my '33 has a 5.0 L pushrod engine so 5000ccs and turns about 1800 rpm at 60 mph.
73400000 / (5000cc X 1800rpm) = 8.15 MPG as the Worst mileage and that would be multiplied by which ever factor you wanted. For "Best" we can multiply 8.15 times 2.4 giving us 19.56 MPG as the expected highway mileage for a carb'd car.
Best = 8.15 x 2.4 = 19.56 mpg
Average City = 8.15 x 2.0 = 16.30 MPG

Example 2: Same as above based on my '33 with Fuel Injection
82670000 / (5000cc X 1800rpm) = 9.19 MPG as the Worst.
Best = 9.19 x 2.4 = 22.0 MPG
Average City = 9.19 x 2.0 = 18.4 MPG

The formulas worked on a Greyhound Bus all the way to a VW Bug. They weren't perfect, but were far more accurate than what the EPA guessed your new 1975 Ford Granada with a Six Banger was going to get. The EPA guessed my Granada was going to get 20 to 24 MPG if I remember correctly! I don't think it ever got 20 MPG with a tail wind and going downhill! Plus it was a slug from 0 to 60.

My '33 Hot Rod comes in pretty close on the Fuel Injected numbers and the '33 isn't much more aerodynamic than my old Granada was! When I was using my '33 as a track car with Northwoods Shelby Club it was getting around 11 - 12 MPG if I recall correctly. My FFR Challenge car with a carburetor barely got above 10 mpg on the same tracks.

Check your own cars against these formulae to see how your real life mileage compares to the estimates calculated. Also, if you are contemplating a "Build" and would like to guess at your expected mileage you could learn quite a bit about displacement, rear gear selection and transmission OD ratios with this.

Best wishes,
Tom Veale

PS: Back in the '70s I submitted my formulas (and the study of around 50 of their road tests) to Road & Track to their "Technical Correspondence" column. They were kind enough to publish it.

[Tom Veale]

One more note on the formulas........................

My study and formulas were based upon essentially all overhead valve pushrod engines not overhead cam engines. More modern power plants have better volumetric efficiency than did the engines in the '70s. So, you might just get better fuel mileage than my calcs with fancy newer engines.

Tom

[Bobby Doug]

Last time I calculated it I was getting 14 mpg. Hopefully my Holley Sniper unit has done a little better tuning and it goes up.

[J R Jones]

One more note on the formulas........................

My study and formulas were based upon essentially all overhead valve pushrod engines not overhead cam engines. More modern power plants have better volumetric efficiency than did the engines in the '70s. So, you might just get better fuel mileage than my calcs with fancy newer engines.

Tom

Tom,
Yeah, did not work for me.
2003 Jaguar XK8 4.2 V8, formula = 10.9; actual = 27 to 29 (71.5 hp/ltr)
2012 Fiat Abarth 1400 I4 formula = 23; actual = 34 to 40 (114 hp/ltr)
2013 Infiniti EX37 3.5 V6 formula = 12.4; actual = 23 (87 hp/ltr)
2006 Toy Tundra 4.7 V8 formula = 9.7; actual = 18 (57.6 hp/ltr)

Summary: weight kills.
jim

[bobl]

Interesting. I find the formula to be pretty accurate. Shows my Duramax getting 16.7 and my dash shows 16.6 lifetime MPG. Shows my RV with Ford V10 getting about 7.5 and that's pretty close to what it gets. JR, looks like you may have neglected to multiply your results by 2 as Tom shows.

[J R Jones]

Interesting. I find the formula to be pretty accurate. Shows my Duramax getting 16.7 and my dash shows 16.6 lifetime MPG. Shows my RV with Ford V10 getting about 7.5 and that's pretty close to what it gets. JR, looks like you may have neglected to multiply your results by 2 as Tom shows.

Bobi,
Yes all my examples are fuel injected and I followed that direction specifically. I now see the 2 and 2.4 in other lines.
BTW I never document mileage by the vehicle computer. I do the division at tank fill, I like empirical research. My brother-in-law gets extraordinary mileage, based on what he sees on his read-out.
I am getting a bit better RV mileage with the Workhorse 494 V8, but 60 gallon fillings are not so frequent recently.
jim

[hineas]

I was thrilled with our gas mileage. Sadly, this is my best gas mileage vehicle!

Around town: 14-15 mpg
Highway (65mph speed limit): 20 mpg
Interstate (80 mph speed limit): 17-19 mpg

We have the 347 with Holley Sniper and 3.55 gears. We also have the 0.64 5th gear in our TKO-600.

[hineas]

I guess there is nothing sad about it being my vehicle with the best mileage! I tell my wife we need to drive it more often because it uses less gas!!!

[Papa]

I was thrilled with our gas mileage. Sadly, this is my best gas mileage vehicle!

Around town: 14-15 mpg
Highway (65mph speed limit): 20 mpg
Interstate (80 mph speed limit): 17-19 mpg

We have the 347 with Holley Sniper and 3.55 gears. We also have the 0.64 5th gear in our TKO-600.


I guess there is nothing sad about it being my vehicle with the best mileage! I tell my wife we need to drive it more often because it uses less gas!!!

My highest performance car gets the best fuel mileage of all my cars. That would be my 2018 BMW M550i with 462hp and 480 lb.ft. of torque in a 4,000+ pound sedan. I average just over 24 mpg in that car.

[Tom Veale]

Hi Jim and Thanks for the work. I think you stopped at the "Worst" calculation and didn't use the "best" and "average" multipliers.

Your '03 Jag would have come in at 21.8 average and 26.2 "best which isn't too far off your marks.
Your Fiat would have come in at 46 or up to 55 Best.
Your Infiniti would have come in at 24.8 Average and 29.8 "best."
and your HeavyWeight Champ Tundra would show average of 19.4 or up to 23 MPG if you were drafting a Semi!!!
Best wishes,
Tom

[Tom Veale]

Certainly aerodynamics (and related driving speed) and weight have a big play in all of this. My original formulas were based upon what I calculated to be X number of cylinder fills per engine revolution assuming no serious restrictions at full throttle. That's where the "worst" came from. The average and best came from what the real world showed for carb'd and injected cars back a while ago. Injected showed significantly better overall mileage over carbs at the time. By coincidence, many of the injected cars at that time were also probably more volumetrically efficient for cylinder filling with twin overhead cams, etc.

My Ford Flex (the Quick Brick) never gets highway mileage any where near what these formulas would suggest unless I'm drafting a Winnebago or Tandem Trailer rig on the interstates!

Best wishes,
Tom

[R. Button]

With 3.27 rear end gears, the T5Z tranny, a 347 cu in engine with a single carb and a foot that I have tried to "tame" ... 14-15 on the open road!

[NiceGuyEddie]

I got 16mpg on a full highway drive/test of 100 miles.

347 with Holley 570, T5 with 0.68 overdrive, 3.55 rear. I'm only 1,300 rpm at 75mph.

At Willow Springs, which is 4,000 - 5,000 rpm the whole way and/or full-throttle I got 4mpg estimating the half tank of fuel I burned.

[mikey likes it!]

City driving = 10-11 mpg
Freeway = same
On track = 5-6
I built it to go fast ! If I wanted mileage... would of bought a Prius....
392, 3.73, mechanical secondaries Holley Ultra, 5-speed tremic 600 and heavy right size 14 foot !
Regarding the Cobra, not concerned with the price of gas... only if it is available !

[BEAR-AvHistory]

My highest performance car gets the best fuel mileage of all my cars. That would be my 2018 BMW M550i with 462hp and 480 lb.ft. of torque in a 4,000+ pound sedan. I average just over 24 mpg in that car.

Think it breaks into two general ranges OHV sub 20MPG - DOHC mid 20MPG. You can't beat the current technology with a carbureted engine. The other major contributor to our over the road mileage is the 8ZF automatic transmissions & soft geared rears that will run 90+MPH a little over 2,000rpm


One more note on the formulas........................

My study and formulas were based upon essentially all overhead valve pushrod engines not overhead cam engines. More modern power plants have better volumetric efficiency than did the engines in the '70s. So, you might just get better fuel mileage than my calcs with fancy newer engines.

Tom

My Cobra/Coyote gets 25mpg all in by the tank full. The TKO-600 & 3:55 rear IIRC its 3000@60MPH

My top runner right now is a 2020 399WHP (DynoJet) BMW Z4 M40i 3.0L DOHC straight 6 which runs consistent 31MPG at 80MPH over a regular 200 mile, no stop, door to door run. Have not tried the 2022 BMW M4C convertible yet, still on 1200 mile break-in.

Its a 3.0L straight 6 @ 503BHP, expect it will be not as good as its little brother. :D Car & Driver got "Observed: all round 22 mpg with a 75-mph Highway Drive at 32 mpg, 0-60MPH 2.8SEC 1/4 mile 11.0SEC @ 125MPH VMAX 180MPH"

[mburger]

My 347 with a ProFlo4 injection is coming off a fresh rebuild with under 700 miles on it. For fun, I plan on getting my mileage on my trip to London Ohio in the morning. 1200 miles of mostly interstate should give me an accurate Highway figure. I’ll update this post with the results.

[GTBradley]

My 347 with a ProFlo4 injection is coming off a fresh rebuild with under 700 miles on it. For fun, I plan on getting my mileage on my trip to London Ohio in the morning. 1200 miles of mostly interstate should give me an accurate Highway figure. I’ll update this post with the results.

Now that is a drive! Good for you. I plan on doing this one of these years from Denver, which is about the same distance. For now I think I'll stick to half the distance to KC for fireworks.

Looking forward to hearing how your trip is...

[Tom Veale]

Mileage results for 2592 miles driven on the Hot Rod Power Tour 2022:
Almost all of this was highway mileage with nearly 1600 of it being Interstate - tank after tank.....

Best mileage = 25 MPG
Worst mileage = 20 MPG
Average Mileage = 22.5 MPG

I didn't do much drafting. It wasn't pleasant in the very high heat (95+°F the whole week) with the soft top and windows out. Too much buffetting from the wind. So the mileage was just what it was driving between 70 and 80 MPH on the interstates and probably 50 to 60 on the two lane back roads top speed and less than that average with small towns, etc.

I have a Tremec 5 speed with a tall overdrive gear (0.68) and 3.55:1 rear gears, 302 pushrod fuel injection engine from a '93 Mustang GT tuned to ~300Hp & 300 Lbs-Ft torque. I turn about 2500 rpm at 75 to 80 MPH.

All in all the '33 is quite the highway car. My arm got tired waving to people in other cars and to Harley riders!

Safe Travels,
Tom