how tough is 40mpg?

[bgd73]

for those that have been acheiving, self repairing, DIY..I need not say much.
I got my first hints of 35mpg on an old dodge omni, 1980s. A friend could not get it to super stoich. Blamed all the obvious, even the carb. Lucky for him his father, the ASE by career, went about too many things to even remember how precise that had to get, to truly have 35mpg. One error in anything and it is 5-10mpg loss.

I mention this with just one recent error I found on my old 22 year project. A gas filler tube, stainless stell, broke clean off at the rubber hose going to the tank...The cause? you wouldn't believe it if I put it into plain laymans term english.
It reminded me of physics that go with 40mpg. There are sections of system that are so slow, you would think it has no function. the carb whistles invisibles. It is so slow in the fuel consumption, the fuel vent becomes fuel mileage...
Anybody else have some physics stories with 40mpg? The real thing is very very intense. I did learn alot over the years, and funny enough most emission standards hinder fuel. I found the convertor, and fuel vent system (charcoal canister) was the only things emoissions related that truly helped. Removing EGR doubled my fuel mileage...

[Tygen1]

You are a strange fellow, but I enjoy trying to decifer your posts.


It seems your gas tank vent was inadequate and thus your fuel mileage was hurt.

[some_other_dave]

I really (still, again!) have no idea what you're saying.

40 MPG isn't that difficult. I have almost broken 50 MPG with my CRX, which the EPA thinks should get me 30 MPG on the freeway. That's in an old-fashioned inline-four engine, not the oft-lauded three-main boxer, BTW.

Small things do add up. I'm surprised that you could double your MPG just by removing the EGR system from your engine; my only thought there is that the existing system must have been really severely messed up! But I'm not surprised you noticed some effect from that, or from your fuel tank vent being plugged. Systems that are broken, or not functioning as originally designed, can definitely hurt your efficiency.

-soD

[elhigh]

I'm driving a bigger, heavier vehicle than your scooby, and I've danced on the ragged edge of 40 at least once. Really, I don't think 40 is all that hard.

It's freaking hard for me, but maybe if I was driving something lighter...like an old GL...

[cfg83]

elhigh -

Originally Posted by elhigh

I'm driving a bigger, heavier vehicle than your scooby, and I've danced on the ragged edge of 40 at least once. Really, I don't think 40 is all that hard.

It's freaking hard for me, but maybe if I was driving something lighter...like an old GL...

That's what I was going to say. It depends on where you start. I could get 30 MPG without trying on my car, so you can argue that 40+ MPG isn't very impressive.

CarloSW2

[tjts1]

How slow can you go? 40mpg is possible in almost any stock vehicle if the speed is low enough.

[Frank Lee]

On my rig I've tried EGR in good working order and EGR blocked off, and didn't notice any fe difference. EGR block = double fe

[robchalmers]

I think its al relative I mean i cruise at 110-120kph don't do any real techniques or have any real mods and I'm on 39, if behaved my self I've sure I'd tick over to 40. If you start with an inline6 or v8 suv then it may be a more considerable challenge. annoyingly my old astra with 4 190lb+ guys,sports equipment etc would cruise at 120 kph with the air on and still get 45+ ....... damn it, I need another diesel!!!

[blueflame]

You Americans need some smaller cars!

Driving my Citroen AX GT pedal to the metal, Gretel, full on speeding ticket material, I still used to get at least 40mpg. I miss those wild days a bit.

[wagonman76]

Depends what you got. I have been able to get 40 mpg with my Celebrity on the last two downstate trips. It seems like it would be easy with something small like an Omni.