How do you Pulse & Glide your diesel vehicle ?

[UFO]

Originally Posted by Hip001

UFO, I only shut down the motor at long lights, or coasting up to a long light. No turning required. IMO the Beetle is a excellent Pulse and Glide car. The shifting is almost effortless in and out of 5th gear with slight throttle pressure. With my Passat the tranny is a little more sloppy so it makes shifting in and out of 5th gear harder to do without using the clutch.

Agreed. I have only recently been coasting, using the 4th option on the poll and have seen some impressive mpg improvements, from about 45 to 47 on the last half of my tank. I am going to continue for the duration of my new tank and see where I end up.

I have an automatic transmission, shifting into N and back into D (gently), and I always leave the engine on.

[JacobAziza]

Originally Posted by UFO

Turning off the engine will save a small amount of fuel, but IMHO doesn't justify the increased steering effort and wear associated with restarting.

It doesn't increase steering effort if you remove the power steering pump.
After getting used to the new feel (a couple days) you will wonder why power steering was ever invented.

[MaxHedrm]

Originally Posted by JacobAziza

It doesn't increase steering effort if you remove the power steering pump.
After getting used to the new feel (a couple days) you will wonder why power steering was ever invented.

Hahah ... from the guy in the truck. It all depends on your steering ratio & steering wheel size and tire width. But you're right, power steering is a luxury. Ideally, you should replace the rack with a non PS rack, but that's rarely an option for most cars from the last 30 years.

[UFO]

Originally Posted by JacobAziza

It doesn't increase steering effort if you remove the power steering pump.
After getting used to the new feel (a couple days) you will wonder why power steering was ever invented.

Yeah, that's not happening. It's a 3000lb car with all the weight in front. My 1978 280Z is similarly weighted, and it's a bear to steer with a manual steering rack. The Beetle never came with manual steering; I'll keep the steering pump, thank you very much.

[Hip001]

My 1966 Beetle and 1955 Ford Fairlane did not have power steering when i owned them in the 80's. I knew no different. I guess I could get use to it but how much gain in mpg could it be? if it's 5mpg+ I'll go remove it today, but if not then I'm keeping it!

Here's a thought: Why not put a clutch on the powersteering shaft like a AC compressor and have it switched off till it's needed while parking? Huge effort and some cost involved but the best of both worlds?

And thought #2: do the same with the alternator.

[euromodder]

Originally Posted by Hip001

My 1966 Beetle and 1955 Ford Fairlane did not have power steering when i owned them in the 80's. I knew no different.

UFO's talking about the New Beetle.

It's a diesel, and they are heavier.
So it's got some serious weight on the front wheels which doesn't go well with unassisted steering.

If I compare my own car to the last car I drove without PS, my current car has some 200 kg (over 400 lbs) more weight on the front wheels.

[Hip001]

[QUOTE=euromodder;230115]UFO's talking about the New Beetle.

It's a diesel, and they are heavier.
QUOTE]


I understand the basic principal and the New Beetle as the topic, but I'd bet the 1955 Fairlane was not any lighter! I could of been the truck driver size steering wheel that made it easier!!!
I still like the clutch on the PS pump idea but have yet to find out how much gain it would be without it. Does anyone actually know if the PS pump puts enough resistance on the motor to make a real mpg difference? I know I know in THEORY it does, B U T is there "real daily driven" proof??

I believe that Ten improvements of 1% = 10% But with that being said (my own personal concern) is a duck tail, plexiglass windowed, stripped down, no AC, radio, or power steering car gonna work for me as a daily driver? and to get more real, bottom line, is it cost worth it in return?
I love this site but from my own perspective at this point in my life, i have to get some real $ return on the cash i spend. While I respect and give props to the people who can throw cash at a project just to say & prove I'm getting 100mpg, I ,on the other hand, do not have the funds for this.

[JacobAziza]

golly, one random comment turns the whole topic...

I finished a cross country trip yesterday.
2004 Toyota Matrix, AT
EPA 30mpg highway.
Before we (girlfriend and I) were getting about 30mpg combined, after installing a scangauge, but no mods.

Before she set off to VA (where I already was) she deleted power steering and added grill blocks. I also added rear wheel skirts during the trip back to CA.
Averaged about 40mpg (still need to calculate the exact number) over about 3000 miles and 9 days.
How much was due to being mostly highway driving, how much to minor aero and how much to PS? No idea. We'll have to see what happens now that we are back to mostly city driving.

But I can say its a 2700 lb car empty (plus 2 people, and 3 months worth of clothes and books and stuff for school and a big cooler of food), front wheel drive, with the original PS rack still installed (just drained of fluid) and the only time there is any noticeable resistance is parallel parking. Even then, its more annoying than it is challenging (including for Jessica).

In my 5500 lb truck I did actually install a gearbox with manual steering ratios, but obviously a much larger vehicle. I'd say turning effort is roughly the same in both.

I do think the power steering pump on a clutch is a brilliant idea.

I just learned all about hydraulic theory in mechanic school.
A hydraulic pump uses the exact same amount of force at all times, whether it is under load or not! When you aren't turning, its resistance is just as high as when you are, its just that the excess pressure, instead of pushing on the steering rack, pushes on a relief valve and cycles back to the reservoir.
Its hard to imagine a bigger waste of energy...
Well, maybe using 25-30% efficiency internal combustion engines to power our cars :P

[UFO]

Originally Posted by JacobAziza

golly, one random comment turns the whole topic...

I do think the power steering pump on a clutch is a brilliant idea.

I just learned all about hydraulic theory in mechanic school.
A hydraulic pump uses the exact same amount of force at all times, whether it is under load or not! When you aren't turning, its resistance is just as high as when you are, its just that the excess pressure, instead of pushing on the steering rack, pushes on a relief valve and cycles back to the reservoir.
Its hard to imagine a bigger waste of energy...
Well, maybe using 25-30% efficiency internal combustion engines to power our cars :P

The energy from maintaining hydraulic pressure is less than you might think. Personally a bigger waste of energy is a gasoline engine, but that's just me.

Now a clutch on the ps pump is not a bad idea, but logistically how would that work? A manual activation is problematic, as one may not expect to use steering until it's needed, then it's not there. The unexpected extra steering effort can cause more problems than necessary.

And a clutch such as the type on an AC compressor uses quite a bit of electrical energy to keep engaged, further reducing the efficiency of the ps pump. I know this site is all about exploring ways to save energy, but this mod is not low-hanging fruit...

[jtbo]

I don't P&G on flat ground, only on those downhills that are just not enough for coasting, there is too much of resistance on flat ground to get any benefit from P&G.

My diesel has a turbo and I have a boost gauge, max boost is 1.0bar and I usually pulse by load of 0.2bar.

0.05bar is the boost when on flat ground and doing 50MPH and car starts really pull only about 0.4-0.5bar.

I do accelerate on 5th gear as turbo provides enough torque to accelerate car well.

Glide is engine on, but I do coast longer hills engine off, diesel takes long time to start with glow plugs and all that.

53.64MPG last tank, has been around there after roads got free from snow.
STW shape of body is not helping gliding part at all.

My technique is to kill the engine and then put key back to run position, that way it is faster to start when needed, but it is not too often that I can do that.

There is no engine management in my car at all, it is all mechanical motor.