success : pulse and coast in neutral at mid speed (40-55 mph)

[groar]

I was using pulse and coast in neutral at low speed, ie in city, and dwl at higher speed (>40 mph). After last maintenance (oil from 10W40 mid-synthetic to 5W40 full synthetic; oil, air and gas filters) I felt more power at my butt-o-meter. I decided to try pulse and coast in neutral at mid speed (40-55 mph). I remarked I can now accelerate from 1100 rpm in 5th gear while before it was only over 1200 rpm.

I think we can say pulse and coast in neutral at 40-55 mph works :

.	mi.	US g.	mpg	% over EPA
Tank1	728.3	13.77	52.88	50.64
Tank2	760.8	14.17	53.69	52.95
Total	1489.1	27.94	53.28	51.79

So I beat best tank mpg and best tank distance twice in a raw

I realized lately that my cost per 100km is lower than the one of a Prius II at EPA rating : 4.43 €/100km vs 4.89 €/100km ie -9% (here gasoline is 12.5% more expensive than diesel) but I generated 116.5 g/km of CO2 ie +12%.

To be noted: previous best tank was in summer with front grill block and rear wheel skirts. These two tanks has been done without any aerodynamic help

Denis.

[Daox]

Congrats groar. P&G really is a great technique.

[Piwoslaw]

Groar, so you've taken you aeromods of? Why?

[groar]

Originally Posted by Piwoslaw

Groar, so you've taken you aeromods of? Why?

Removed the hubcaps and rear wheel skirts because they were build with cardboard. Since I have bought some flatter hubcaps and I have in my todo to close their holes.

Removed the front grill block as I had a leak near the water pump and the engine was overheating.

I do want to put some front grill block and rear wheel skirts back, build in coroplast, but it's too cold outside and day is too short by now...
As the front is very flat, I think I'll try to make the front grill block convex to lower the high pressure zone in front of the grill. I'll also try a upper grill block, but currently I don't see how to fix it without fixing it at both hood and bumper.

Denis.

[groar]

Originally Posted by groar

I think we can say pulse and coast in neutral at 40-55 mph works :






So I beat best tank mpg and best tank distance twice in a raw

With the last tank :

.	mi.	US g.	mpg	% over EPA
Tank1	728.3	13.77	52.88	50.64
Tank2	760.8	14.17	53.69	52.95
Tank3	803.0	14.59	55.02	56.74
Total	2292.2	42.54	53.88	53.48
Average	764.1	14.18

So I beat best tank mpg and best tank distance three times in a raw but I won't take the risk again to drive 100 km once the idiot light switched on, even if the tank theoretically contains 15.85 g.

I realized lately that my cost per 100km is lower than the one of a Prius II at EPA rating : 4.43 €/100km vs 4.89 €/100km ie -9% (here gasoline is 12.5% more expensive than diesel) but I generated 116.5 g/km of CO2 ie +12%.

Last tank: 4.19 €/100km and 113.7 g/km.
About the Prius III, it has been announced at 89 g/km but I have to improve myself by 22% to achieve such a CO2 emission

To be noted: previous best tank was in summer with front grill block and rear wheel skirts. These two tanks has been done without any aerodynamic help

I installed my coroplast rear wheel skirts. My butt-o-meter says it does improves things but this may be that I want it so much that I'm affected by the placebo effect Hope they will at least permit me to achieve the Prius II's CO2 emissions (104 g/km).

Denis.

[1337]

Originally Posted by groar

I was using pulse and coast in neutral at low speed, ie in city, and dwl at higher speed (>40 mph). After last maintenance (oil from 10W40 mid-synthetic to 5W40 full synthetic; oil, air and gas filters) I felt more power at my butt-o-meter. I decided to try pulse and coast in neutral at mid speed (40-55 mph). I remarked I can now accelerate from 1100 rpm in 5th gear while before it was only over 1200 rpm.

I'm no expert on your car, but most modern engines can run with even lighter oils that what you're running. You might want to call your dealer and ask what the lowest weight they recommend is.

My Mazda's manual says to run 10W-30, but I according to the Mazda dealer, 5W-20 and 0W-20 are more than satisfactory for lubricating the engine. The manual says 10W-30 because lighter weight oils were less readily available when my car was made.

[groar]

Originally Posted by 1337

I'm no expert on your car, but most modern engines can run with even lighter oils that what you're running. You might want to call your dealer and ask what the lowest weight they recommend is.

From another thread :

Originally Posted by groar

From car's manual, any *w40 oil is OK from 0w40 and up. The mechanic uses 10w40 by default and was very astonished that I was asking for 0/5w oil. He didn't had any 0w oil.

Depending if this thinner oil makes the engine loose more oil I may try a 5w30 oil the next time. Also if I understand correctly oil weights, a w30 oil doesn't support temperatures as high as a w40 oil and I don't want to break my engine. Finally I don't remember when I did a trip longer than 75 kms (45 miles) with that car, my daily commute is 30 km (20 miles), so going from 10w40 to 5w40 is certainly more important than going to 10w30.

Denis.

[daqcivic]

Groar,

Can you describe your pulse method a little? As in, how much throttle % are you giving? Do you vary the throttle by gear or by the RPM in a given gear?

I ask because I'm trying to get a feel for how P&G has worked for different people. I tried 1 tank P&G in city, using 60-80% throttle, and my FE got way WORSE. I am currently trying it with about 40-50%, and this seems to be giving very marginal improvements.

[Vekke]

I use push and glide in speeds below 50 mph. Over that speeds I think the gain is so little that i dont bother to stress my engine and gearbox... On my diesel TDI I use flat out gaspedal method for acceleration...

[groar]

With the two last tanks, driven with rear wheel skirts :

.	mi.	US g.	mpg	% over EPA
Tank1	728.3	13.77	52.88	50.64
Tank2	760.8	14.17	53.69	52.95
Tank3	803.0	14.59	55.02	56.74
Tank4	797.0	14.04	56.78	61.73
Tank5	660.9	11.38	58.08	65.45
Total	3750.0	67.95	55.18	57.18
Average	750.0	13.59

The skirts do help in coasting duration. On some small down slopes before I was loosing a little speed and now I gain a little speed. The skirts change the feeling of the car so much that I'm accelerating too fast and often drive over my max speed.
While I was improving by 4%/tank without the skirts, I'm improving by 5.5%/tank with the skirts, ie a +33% improvement in the improvement

Denis.