Fuel economy

[Rapid]

I took a short mile trip this weekend. On the way there I drove at 80/85 and got 17.8 mpg. On the way back stayed below 70 and got 21.9 mpg. I saved 8 bucks by spending a little more time on the road. I am going to stay below 2000 rpm shift point and see what I can do on my daily drive which is about 50/50 hwy and city and 11 miles each way.

 

[bnickel]

pretty good, let us know how the short shifting works.

 

[wild70stang]

What is your set up like? Also does anyone know what the difference in mpg a manual has over an auto tranny w/o overdrive. I am getting 18 hwy going granny speed (65) with 3 speed auto, stock 302 with 500 cfm Carter AFB 4bbl, free air hog filter performance filter (if only K & N were free), 8mm wires and Pertronix ignition system with coil. I'm getting ready to install an Autolite 4100 in hopes of getting 20, then sell my carter.

 

[70vert]

you know what, in my other life I'm on a hypermiling forum Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - their tips WORK. The main technique is pulse and glide and slowing down, and I've used that to get an all-time high of 49mpg on a Scion xB on a long trip, with an average of highway and city driving of 40mpg, or 38% over EPA.

The pulse and glide thing should work well if you have a manual tranny, and our torque helps us out under 2k rpm.

The only accurate mileage measurement I have is Google Maps, and that requires some planning, lol, or I'd compare. But the hypermiling techniques WORK - I was skeptical, but my first tank convinced me. I wouldn't do Engine Off Coasting (EOC) in my classic, though - don't want the wear and tear on the starter and need the power steering.

If you have a typical 2.79 rear that many 3-speeds came with and like I do, you can get some great mileage by loping along on the freeway in 5th when you switch to a manual.

 

[Rapid]

What is your set up like? Also does anyone know what the difference in mpg a manual has over an auto tranny w/o overdrive. I am getting 18 hwy going granny speed (65) with 3 speed auto, stock 302 with 500 cfm Carter AFB 4bbl, free air hog filter performance filter (if only K & N were free), 8mm wires and Pertronix ignition system with coil. I'm getting ready to install an Autolite 4100 in hopes of getting 20, then sell my carter.

I am running a T5Z with a 3:55 Trutrac Diff, 500 CFM Edelbrock, Performer intake and cam, MSD ignition, recently dynoed at 197 RWHP.

 

[BornInAFord]

Rapid, thanks for reporting your mileage! Your setup is very similar to mine power wise--I have a 5.0L/Edelbrock Performer heads/HO cam/Torker 289 intake/T5z/3.40TL (dyno'd at 198.4rwhp)--but I also have a roller block, roller rockers, windage tray, electric fan, synthetic oil and an 480cfm Autolite 4100 (this carburetor and cutting friction are key for mileage, imo). My best so far is 27.8mpg on 87 octane in ~170miles of mountainous driving--equivalent to 30+ for flatlanders. We should both shoot for 30. I'd probably only get 20-22 on your daily drive situation, though.

Hypermiling techiques do work (although some are dangerous). Having manual brakes, transmission and steering means I could coast with the engine off, but this is apparently illegal here in Oregon. I do do other things like shutting the engine off when sitting at lights I know will be waiting at longer than a minute.

Daniel

 

[70vert]

yeah, the pulse and glide techniques and coasting with engine on are techniques anyone could use with a manual trans, and if I had manual steering as well as the manual brakes I already have, I would seriously consider turning the engine off on long downhills. Wears on ignition and starter, though, so take that into consideration, although you can shift to a high gear and bump start at the bottom of the hill, which I occasionally do in my Scion.

At a stoplight, though, keep in mind that if you're in neutral and are rear ended, especially if you don't have a headrest like a '69-70, you are SCREWED. Please be careful and be aware of your surroundings if you try any of these techniques. Having it in gear just might save you serious injury or worse.

 

[SadbutTrue]

I am running a T5Z with a 3:55 Trutrac Diff, 500 CFM Edelbrock, Performer intake and cam, MSD ignition, recently dynoed at 197 RWHP.

Any exhaust mods? Just curious because I like to get as much dyno 'history' on various SBF engine combos as possible.

 

[SadbutTrue]

yeah, the pulse and glide techniques and coasting with engine on are techniques anyone could use with a manual trans, and if I had manual steering as well as the manual brakes I already have, I would seriously consider turning the engine off on long downhills. Wears on ignition and starter, though, so take that into consideration, although you can shift to a high gear and bump start at the bottom of the hill, which I occasionally do in my Scion.

At a stoplight, though, keep in mind that if you're in neutral and are rear ended, especially if you don't have a headrest like a '69-70, you are SCREWED. Please be careful and be aware of your surroundings if you try any of these techniques. Having it in gear just might save you serious injury or worse.

Are transmissions actually okay with coasting in neutral? Last time I did that (going down the grapevine in my cadillac) I started smelling something burning and put it back in D before I got more than a few miles..

And did you mean coasting with the engine off?

 

[SadbutTrue]

Rapid, thanks for reporting your mileage! Your setup is very similar to mine power wise--I have a 5.0L/Edelbrock Performer heads/HO cam/Torker 289 intake/T5z/3.40TL (dyno'd at 198.4rwhp)--but I also have a roller block, roller rockers, windage tray, electric fan, synthetic oil and an 480cfm Autolite 4100 (this carburetor and cutting friction are key for mileage, imo). My best so far is 27.8mpg on 87 octane in ~170miles of mountainous driving--equivalent to 30+ for flatlanders. We should both shoot for 30. I'd probably only get 20-22 on your daily drive situation, though.

Hypermiling techiques do work (although some are dangerous). Having manual brakes, transmission and steering means I could coast with the engine off, but this is apparently illegal here in Oregon. I do do other things like shutting the engine off when sitting at lights I know will be waiting at longer than a minute.

Daniel

Outside the Torker (isn't that an old school single plane? if so i would think a performer might do slightly better), sounds like you have basically the best setup possible for mileage. Cool

 

[BornInAFord]

The torker 289 (twisted torker) is old school, but still a very good intake for the SBF. I actually moved from Performer to Stealth to T289, and like the single plane better as an all around intake. I know I am in the minority, but my experience is that the small plenum and conservatively sized and shaped ports of the T289 (and similar Weiand 7515) may help the flow efficiency and reduce pumping losses into the engine. I am using a 1" spacer to help with the low end carb signal. Peak torque is at ~3850RPM, but I get 95% of that from 2000 (where dyno run started) to 4800RPM. Peak power is at 5400. That's as wide or wider of a torque curve as most good dual planes get, and I get great street performance and excellent tip-in throttle response. I maybe do lose a little torque from idle to 1500, but vacuum values are ~18" at idle (750rpm), so intake is still working pretty well.

60MPH is at 1700RPM, and this is probably close to where my peak efficiency is combo wise, which may help with mileage figures, too.

 

[70vert]

Engine on, not off, and manual trans

Are transmissions actually okay with coasting in neutral? Last time I did that (going down the grapevine in my cadillac) I started smelling something burning and put it back in D before I got more than a few miles..

And did you mean coasting with the engine off?

I normally coast with engine on when I am hypermiling the Scion and occasionally in the Mustang. I never coast with engine off (EOC for Engine Off Coasting) in the Mustang and rarely in the Scion just because I don't want to wear out starter and ignition - there are some 38 year old parts in there.

If I had an auto trans I wouldn't do it unless I knew a LOT about how it behaves in neutral. It seems that every tranny, or at least every generation from a given manufacturer, is different. They talk about this at length on ecomodder.com.

However, I would (and have) done it in a rental (engine on coasting) and beat the EPA rating for the rented Focus I was driving, without even checking inflation on the tires.

 

[Rapid]

Any exhaust mods? Just curious because I like to get as much dyno 'history' on various SBF engine combos as possible.

I am running a stock "K" code exhaust. HIPO manifolds, "H" pipe and I think 2.25 tubes.

I have not tried any of the hyper milage techniques. Just looking at what using a little restraint might do. I don't like shifting at 2K. I'm going to try 2.5K next week to compare. Traffic is eating me up when I ease off...

 

[Rapid]

Results of shifting before 2000 and easy on the gas only netted me 12.7 MPG in city driving. I am changing the accelerator pump to the lowest setting and am going to raise my shift point to 2500 which feels more natural and see what happens.