mpg method

[73azbronco]

I forgot to mention, if anyone driving a Prius like car asks about your mileage, I respond with either 63MPG or 25miles per pound of freshly squozen baby seal (or insert favorite endangered species here) juice. This or, "I don't get miles per gallon, I get 50 grins per mile, and you in that Prius get what, zero?"

 

[Skiddy]

I always tried to do things to get better mileage out of my '71 when I was daily driving it. But I never once thought of the payback period. Total cost was never a concern (other than flat out not being able to afford some things) and I simply wanted it to run the best it could, while getting the best mileage possible.
Most of my mods gained performance or drivability, while never lowering mileage. So even though most of them did not gain me a think in the MPG department, I considered it a total win to not lose MPG either!
Small 4bbl carbs, better ignitions, different tires, etc. All did what I expected and made the drive more fun without hurting mileage.

I don't agree that lower gearing is automatically worse, or that taller gearing is better for mileage. Depends on the overall package.
In the case of my fuel injected '68 with 4.56's and just barely 30" tall tires, I bet I can increase the fuel economy with taller gears.
I can squeak 20mpg out of the 5.0 now if I stick to 55 mph and don't spend a single minute driving in the city. If I try the 4.11's I bet that goes up a tick because I can lower the rpm without the engine struggling.
Around town it's exactly the same mileage as my '71 was with stock engine.

Paul

one thing people don't take into consideration is the terrain, wind ect..
like driving around here mostly flat and get pretty good mileage but if the wind is blowing it's a lot different. now if I lived in the mountains and wind blowing all the time my mileage would really suck
there are a lot factors that affect mpg

 

[sykanr0ng]

Getting better fuel mileage is not only about saving money.
Being able to go farther before you need a tank of fuel makes more trips possible since you are not tied to the gas stations on a short leash.

With so many having only one tank these days that restricts their range even more.

 

[73azbronco]

Of all the things I think about with a 40 plus year old truck, gas is the last of my worries

 

[DirtDonk]

The black eye that Prius drivers get is because most of them drive with the power meter rather than the speedometer...

Yeah, I don't care who you are (or what you drive), don't hyper-mile on other people's time!

One gratifying change of pace lately is that as often as not, I'm the one that has to get out of the way of a Prius driver whipping down the fast-lane even faster than me. Also, more and more of the slower ones are obviously attempting to stay in the right lanes when they can. Very gratifying indeed.

It has never bothered me one iota to get out of someone's way that's going faster than me. I consider it my duty to be considerate, which makes driving safer. Doesn't hurt my feelings at all to not be the first one in line.
After all, you're NEVER the first one down that road.
I just hope that they all do the same when it's their turn.

Paul

 

[jckkys]

I did a lot of experimenting in search of better mileage in my new '74. The oil crises was just getting behind us and everyone was downsizing. I wasn't giving up my Bronco. So I did everything I heard would help MPGs. The OE tires were 235/R75s or 29" and by keeping it at 55MPH I got 15 MPGs. My new stock '77 had the same 235/R75s, C4, and 3.50 gears. It also got 15MPGs. I got 31" tires and lost about 1 MPG. The 351 regained that 1 MPG. One long road trip with a Holley Economizer 2300 got 19 MPGs at 65 MPH but the engine ran hot from the lean mixture. The Autolite 2100 and 4100 carbs get good MPGs and drive better than the Economizer. They're a lot better off road too.
A good state of tune, well aired up tires, speeds <60, and an optimized timing curve all help. My carburetor is every bit as reliable as the EFI in my 2 other cars. Gas is historically cheap now so drive your EB and enjoy.

 

[No Hay]

I have the same 302, C4, 3:50's, 33x12.5 tires, Edelbrock 650 and bigger cam.

From Portland to Florence (3 hours), both directions, 70 mph, I got 12.3 mpg. I thought that was pretty good for a flying brick. ;D

I would never use it as a DD, so the mileage doesn't matter.

Like others said, "smiles per mile" is the only reason I own and drive it.

 

[5001craig]

Well, you could always go with a stroker. Lol. I filled-up before and after a trip to a car show (18 miles each way) and got 5.167 MPG. There was a little bit of hammering involved. ;D

 

[Pa PITT]

... GAS MILEAGE .. THOSE Words Should not be allowed to be used in the same sentence with the name BRONCO.
so my org gas Bronco only got 4 mpg. on my farm.. SO I swapped to a 4BT Cummings Diesel that everyone said got 30 mpg... NOT IN A BRONCO .. I get about 10 on the farm.
But one time in a car show cruise I got 26 mpg. MOST OF THAT WAS AT 30 MPH.

 

[broncnaz]

Basically making sure your engine is tuned correctly will probably net you the most increase. A few people have gave some tips there. Engine timing is a big one, then overall jetting. These are pretty cheap options that can make improvements. EFi doesn't always gain you mileage unless your engine was out of tune to start with and as was said OD tranny's usually need to be coupled with axle gearing changes so more money before you see any gain even then you may not gain. Its really all a package deal. Engine, gearing, tire size, and driving needs.
One thing I consider is the camshaft as it basically controls where your power is made. It makes a big difference. Then I would also suggest a exhaust system that's a little bigger than stock and of course overall tuning.
EFI is nice and you may see a slight gain over a well tuned carbed engine, New OD trannys are nice as well and again you may see gains more due to less parasitic power loss of the newer stuff and the OD function.
So best bang for the buck is just ensuring what you have now is tuned as well as it can be. If its low mileage you may want to swap camshafts. IF its high mileage well you may not get any gains from tuning it may be time for a new engine or a engine swap. Then your bang for the buck is kinda out the window at that point so you go the route you think is best and hopefully you get mileage increase and better driveability.

 

[Pkdupont]

Rear end ratio for drivability

So my rear end (4.11) is binding. For 95% road driving, is there any advantage to changing the ratio during a rebuild or swap out? Not so concerned about MPG itself.
It has a 302 bored out 30/1000s, 4 BBL carburetor, 3 speed manual.
Thanks

 

[nvrstuk]

Everybody's right...

Tire width
Vehicle height (much more of a aerodynamic affect than most realize)
Speed
...and everything else mentioned above

Good luck doing much of anything to the stock '77 as it's a detuned, emission designed small V8

BEST stock Bronco engine for mileage was the 289. Stock 2bbl or small 4 bbl and 17-19 could be had everyday at 70mph. Figured with pencil/paper with fill ups on corrected odometer.

With the same gears, bit narrower tire size, driver following me on a 1,000 mile trip loaded with the same weight in a '69 Bronco and never, not once got over 14.5mpg but never got below 14mpg.

My Dad and I did this at least 5 times on fishing trips to Northern BC... his '69 302, my '68 289.

 

[Broncobowsher]

So my rear end (4.11) is binding. For 95% road driving, is there any advantage to changing the ratio during a rebuild or swap out? Not so concerned about MPG itself.
It has a 302 bored out 30/1000s, 4 BBL carburetor, 3 speed manual.
Thanks

Short answer, no.

Since you have a 4WD it isn't just the rear axle gearing that matters. The front has to match as well. So you would need to regear the front axle to ever get the usefulness of 4WD. If you don't plan to use 4WD, time to get another vehicle.

Also you have not provided enough information. Sounds like you have a fairly stock engine that has been rebuilt. and a 3-speed so we know the top gear is 1:1. But what size tires?

 

[Pkdupont]

Thanks. Here's a bit more info.
It's the original stock 302, bored out 30/1000s with an upgraded edelbrock cam (I don't have the model # handy) and 4 barrel carburetor.
Currently on 31 inch tires, but I might bump them up, as i installed a body lift.
I definitely will expect to make use of the 4 wheel drive on my winter commute and the occasional foray into the mountains

 

[Broncobowsher]

Put another set of 4.10s back in it. Run some 33" tires. About as good as you can get without getting into a lot of expensive parts.

 

[DirtDonk]

So my rear end (4.11) is binding.

What do you mean by it's binding? Do you have a limited slip that's just in need of some new lube?
Is it making noise, or giving you trouble around the corners? Or have you spun the pinion and you can feel the gears binding up every so often?

For 95% road driving, is there any advantage to changing the ratio during a rebuild or swap out?

Sure. But there are legit arguments for both sides. Some of which you've already heard.
However more of them are in favor of keeping the 4.11's you have now.

Especially if you stay with 31" or larger tires. While taller 3.50's or even 3.73's might lower your freeway RPM levels, the loss in stoplight power and the more off-road friendly 4.11's have might be enough to negate the advantage of more street-friendly gears. Higher engine speeds might seem a negative, but with a vehicle this heavy and with this much rolling resistance and aero resistance, more engine is a good thing!

With a perfect running engine and/or EFI the taller 3.50 might have an advantage while still running 31" tires. With an automatic trans you could get away with taller gearing more often. But with a carb'ed engine and a 3-speed manual (it is a manual?) then stick with the 4.11.
Especially if you're hoping to go larger in tire size!

Since you've already expressed an interest in going to a larger tire size, and said you intend to go off-roading with it sometimes, then as 'bowsher said before. No, stick with your existing gear ratio.

Not so concerned about MPG itself.

Good. But in this case your mileage might even be better with the lower gearing. Hard to tell, but it is for many of us.

Paul

 

[Rustytruck]

It depends where you do most of your driving. If you did 3,000 mile drive from California to Florida a numerically lower gear set might give you slightly better mileage. If your doing stop and go driving a numerically higher gear set might get you better mileage. The Bronco is a gas pig in stop and go driving it just plain takes allot of gas to get it up and moving. The 4:11 gets you up and going quicker and easier than 3.50 gearing will. The sooner you get up on power and you get up into the more efficient RPM range and the moving resistance has been over come. Get the gearing wrong its like filling a 5 gallon bucket with a garden hose and there is a hole in the bucket half way up. Want to fill up that bucket anyway, your going to have to add more water to overcome the leak.

 

[sprdv1]

Put another set of 4.10s back in it. Run some 33" tires. About as good as you can get without getting into a lot of expensive parts.

Yes sir, I'd say do that same thing....

 

[cs_88]

I found that using the Bronco as a daily driver takes away the actual enjoyment of having a Bronco.
If the Bronco is a weekend rig there is no concern about gas mileage, it's all about enjoying the ride.
As soon as it becomes a daily driver it becomes all about how much it's costing to drive it... and that sucks.
Just sayin.

 

[sykanr0ng]

I found that using the Bronco as a daily driver takes away the actual enjoyment of having a Bronco.
If the Bronco is a weekend rig there is no concern about gas mileage, it's all about enjoying the ride.
As soon as it becomes a daily driver it becomes all about how much it's costing to drive it... and that sucks.
Just sayin.

I have used Broncos as my daily driver in the past and found myself only caring about gas mileage in regard to when I needed to fill it up.
I enjoyed them too much to care about fewer miles per gallon.

You should remind yourself to always enjoy driving your Bronco, if you want to obsess about gas mileage drive a Prius.