other Mpg Results Of 3,400 Mile Trip In '74 02 With 5 Speed

[1965GTFB]

Just wanted to share this info to help answer some of the MPG questions that come up from time to time.

Car: 1974 2002, Weber 32/36, stock air cleaner, stock exhaust manifold, 320i 5 speed, stock 13" tire size, not sure of rear ratio will check and update.

Trip: 3,400 miles from Nor.Cal

-up I5

-side trip through Lake Oswego in Portland OR. area

-side trip out Hwy 11 south of Bellingham WA.

-at Bellingham over on Hwy 539 then Hwy 546 then Hwy 11 to Trans Canada Hwy 1.

-Trans Canada Hwy 1 over the Canadian Rockies all the way to Banff, Alberta, Canada.

-Down TCH 1 to Calgary

-Down Can Hwy 2 to US Hwy 89 to Hwy 287 to Helena, MT., included some dirt roads due to construction.

-Hwy 12 to Hwy 287 to Hwy 90 to Hwy 89 to Yellowstone NP with lots of stops at the sitesand some dirt roads du to construction, out to West Yellowstone via 20/191/287.

-Back into Yellowstone via 20/191/287 and down to Old Faithful area with lots of stops.

-Down Hwy 89/287/191 to Jackson, over Hwy 22 Teton Pass then Hwy 33 & 31 to Hwy 26 to Hwy 15 at Idaho Falls,ID down 15 to Twin Falls, ID.

-Down Hwy 74 and 93 to Hwy 80 and through BORING I80 through Nevada, then scenic I80 in CA. to home.

 

Driving the limit or above, lots of 2 lane roads with 60-65mph limits, lots of curves and right foot fun driving.

 

Results:

Best leg - 32.95mpg

Worst leg - 21.81(Yellowstone-lots of stops, hills, traffic, etc.)

Total avg for trip - 26.84

 

Observations - Best MPG legs in Oregon, Washington, Canada, Montana(non Calif. full of junk additives gas????)

A leg I thought would be one of the best(fill up just West of Reno and LOTS of coasting in neutral from Reno/Tahoe down to Sacramento and on to North Bay area was only 25.6 mpg(again, Calif. gas with lots of hippe additives????)

 

Looking forward to future trips with a more open air cleaner, dumping all the vac. lines and going with one from Dist. to manifold vac. and maybe headers.

[TR]

Thanks and great photos.  Living here on the East coast I miss the mountains out West and there is no better car (other than a convertible) to fully enjoy the views.

[ray_]

Cool.

 

How do you know your odo is accurate?

 

Cheers,

[saaron]

FWIW, gang:

 

I checked the highway mileage on my tii on the way / way back from Vintage.  Going east across Ohio to West Virginia, through the mountains (OK, not like out West) of WV and Virginia, down to Winston Salem.  So some elevation gain, and then going back down as you go into NC.

 

JohnnySquare and I got 27 - 29 mpg, depending on the tank.  Used a GPS to calculate the miles.  Drove from 65 mph to 75 mpg most of the time.  Highway miles, very little stop and go.  

 

Car is Euro '72 tii.  Stock except electronic ignition (Crane).  4 speed.  Stock wheels and tires (13" early alloys).  3:45 rear end.  

 

I was surprised it was that good.  I thought 25 mpg would be good, going that speed.  

 

Scott

[peterschop]

Wow, 21 to 33 MPG. This gives me something to work on. After driving my '74 2002A for a year without a working odometer, I finally got around to repairing it. I was able to confirm what I thought. I am getting under 18 MPG. Things I think will help will be swap the automatic for a 5 speed and replace the vacuum advance module that is not working. My goal is to get the MPG into the mid 20"s.

[1965GTFB]

Cool.

 

How do you know your odo is accurate?

 

Cheers,

I do think my odo might be off a little.  I think it reads a little slow.  So that would mean it's showing less mileage then really travled, right?  Which would also mean the MPG was better?

[Preyupy]

Don't hook the vacuum from the distributor line directly to manifold vacuum.  It is designed to see carburetor venturi vacuum (vacuum is produced when you are on the throttle, as opposed to manifold vacuum that is produced when you are OFF the throttle)  you will have your advance working backwards and your fuel mileage and performance will suffer.

[1965GTFB]

Don't hook the vacuum from the distributor line directly to manifold vacuum.  It is designed to see carburetor venturi vacuum (vacuum is produced when you are on the throttle, as opposed to manifold vacuum that is produced when you are OFF the throttle)  you will have your advance working backwards and your fuel mileage and performance will suffer.

So it needs to hook up to vac above the butterflies?

[peterschop]

So it needs to hook up to vac above the butterflies?

Depends on if you have a vacuum advance or retard. Advance gets hooked up above the butterflies and retard below. In my case, I have a distributor from a 320i that has both advance and retard. The retard side will hold a vacuum but the advance will not. Therefore I have the retard attached below the butterflies and the advance line plugged. This could be part of the reason for my bad gas mileage. I need to find a working retard/advance vacuum module.

[eurotrash]

Scott, your car has a 3.43 diff.  Making it similar to a 5 speed final drive.

[saaron]

Scott, your car has a 3.43 diff.  Making it similar to a 5 speed final drive.

 

Yeah, I'm sure the 3:45 gear helps a lot when it comes to mileage on the highway.  Just not at the drag strip.  

 

Scott 

[KFunk]

If it helps, I managed to get some decent numbers for fuel mileage on my car (far from stock) this past weekend while driving to Northeast Wisconsin and back.

 

I've got a 292 cam, Weber 40 DCOEs, 9.5:1 pistons, 3.91 diff, 5-speed, header/exhaust, electronic ignition, etc.

The carbs probably need re-jetted a little, but seem pretty damn good as is.

 

Normally with mixed driving (curvy roads, town, and highway), I get around 24 MPG.

 

On this past weekend's trip, the car was fully loaded with a bunch of camping gear, trunk and backseat full, and passenger.

The worst mileage I got was around 21.5MPG.  That involved lots of stop and go driving in town, in torrential rains, several cold starts, etc.

 

The best mileage I got was 27.2 MPG, which also included a heavy load, and mostly running at 70 to 75mph on the highway for one straight shot.  Not too bad I don't think, for some big sloppy carbs with a heavy load going at high speeds (lots of wind resistance).

Maybe with better conditions, I could get closer to 30, which would be great.

Edited October 9, 2013 by KFunk

[saaron]

The best mileage I got was 27.2 MPG, which also included a heavy load, and mostly running at 70 to 75mph on the highway for one straight shot.  Not too bad I don't think, for some big sloppy carbs with a heavy load going at high speeds (lots of wind resistance).

 

That is pretty awesome, man.  I bet that 5 speed helps a ton.

 

Scott 

[Rocan]

This is what I get on average, in mostly heavy NYC traffic, to and from school. This is with a tired motor (actually pulled it off the road soon after the last marked fill-up because it has a bad knock), stock 4 speed, 3.90 diff. Weber 32/36, megajolt ignition system, oversized valves in the head, not sure what cam but bigger than stock for sure. 

 

https://www.fuelly.com/driver/rocan/2002?

 

I'm going to shoot for 35-40mpg with megasquirt and a 5 speed, as well as some aero mods (bellypan, for example) 

[TobyB]

Jenn's car routinely got 30+ mpg on long trips- 5 speed, 3.64 diff, 32/36 jetted pretty lean, cam ground more for torque than hp.

 

Mine never did better than about 25, but it was always tuned more for fun than profit.

 

t