Pulse and glide technique, does it really work?

[dude7691]

Hi guys first off I love driving hard on occasion but it's important to me to hypermile 99% of the time being young I need to save money whenever I can so just wanted to check something out

I've heard of the pulse and glide technique which sounds promising going from 50-60mph then coasting back to 50 in neutral and repeating. I wouldn't turn the engine off as that seems far too dangerous. I'm just curious as to whether this would potentially damage the gearbox, clutch or engine over time? The last thing I want is to be saving money on fuel then have a ruined car �� I've managed to get 44.5mpg out of a 1.4 Kia Rio quoted 45.4mpg combined but it is 10yrs old now. When I got the car it took some redex to get it from 35 up to 45. That's going 55mph everywhere with a lot of town driving and it sits at 2600RPM @55. I've done a lot of hypermiling in the past and know some advanced stuff but only heard about this today. This method makes sense as less mechanical friction = better efficiency. just wondering if it's worth trying this technique thank you

[Fat Charlie]

Do it.

The accelerating is normal for the gearbox. If you're proficient with a manual, you'll be just fine with gliding in neutral.

When I started hypermiling I was in a 20 mpg car that I had been getting 22 mpg out of. I went up to 28 on my first tank. The car had 160,XXX miles on it when I started this, and 207,XXX when I traded it in on my Honda. Original clutch. I've put over 125,000 miles on the Honda so far, on its original clutch.

And welcome!

[deluxx]

The only negative thing I can think of is increased battery wear.
If you only drive short trips in bad conditions with headlights, wipers, defroster, heater fan or bad weather often and you can coast 3/10 miles with the engine off you should think of getting a deep cycle battery and a decent charger to charge it daily.
If you only EOC down a hill to a stop sign once or twice a trip you will still see a big savings.
Another thing to do is eoc and pulse and glide however much you want and just idle the last mile or so of the trip to recharge the battery.
The battery in my car is horribly undersized, Motorcycle or Lawn Mower sized. I'm planning to find a used deep cycle battery or two and mount them in the trunk with a charger wired in so when I get home I can simply plug in a single cord and charge it. Should be around $100 because I already have an old schumacher 10A charger.

[dude7691]

Originally Posted by deluxx

The only negative thing I can think of is increased battery wear.
If you only drive short trips in bad conditions with headlights, wipers, defroster, heater fan or bad weather often and you can coast 3/10 miles with the engine off you should think of getting a deep cycle battery and a decent charger to charge it daily.
If you only EOC down a hill to a stop sign once or twice a trip you will still see a big savings.
Another thing to do is eoc and pulse and glide however much you want and just idle the last mile or so of the trip to recharge the battery.
The battery in my car is horribly undersized, Motorcycle or Lawn Mower sized. I'm planning to find a used deep cycle battery or two and mount them in the trunk with a charger wired in so when I get home I can simply plug in a single cord and charge it. Should be around $100 because I already have an old schumacher 10A charger.

That makes sense. There's quite a few big hills on my daily commute so will definitely EOC on those once I've had some practice with it. I'd say my driving is 50% day and night but obviously some rain too. Thank you for this

[dude7691]

Also question to both people who responded. With my specific vehicle does 55 @2600rpm sound a bit high to you? I haven't got a fuel consumption meter so judging on the fly is impossible. But around 45mph I drop to around 2300RPM. the peak torque in my car is around 4700 which obviously I'm not going to drive at that can't be more efficient but at night doing P&G from 45-55 sounds better. I need to be careful in my car though as it's old and I don't want to place too much extra load on the electrics with EOC. With the exception of those huge hills I'll stick to neutral for now.

[deluxx]

Its not that old.. I doubt you will have any electrical issues...(?) all hybrids turn the engine on and off with a computer but we are better. I don't know about the Rpm's but seems normal. Use a Tourqe app or a ScangaugeII. For me personally I treat it like the water or lights.. do you leave the water on when you ain't using it? Do you leave the lights on? why leave the motor on?

[litesong]

Originally Posted by dude7691

....my specific vehicle does 55 @2600rpm sound a bit high to you?

My manual Hyundai Accent at 60MPH is 3000rpms with standard 175x70x14 inch tires. Three years ago, I used oversized 205x65x15 inch tires & wheels, now giving 2650 rpms at 60. Its not like an extra gear in the transmission, but the big tires wonderfully reduce rpms. Try to get the biggest tires you can & still clear the wheel wells & mudflaps. With the big tires, you should drive & corner easy, to reduce suspension stress. The one problem is you will have no clearance for snow chains & you'll have to get smaller snow tires for the winter.

[deluxx]

Isnt the bigger tire giving you worse MPG for stops and starts? Is this a strictly highway vehicle?

[Fat Charlie]

2300 RPM at 55 doesn't seem off. Old or not, the gear ratios shouldn't change with age. In regular, non-p&g driving, about 45 mph is where my Fit's best mpg lies.

As you get used to p&g and EOC, it'll get seamless. No one outside will be able to tell if you're in gear or if your engine is running.

I did well in my last car with slightly larger tires.

Ge a meter. ScanGauge, UltraGauge, they're the best. I haven't used Torque since it was new, so I can't tell if its fuel readings have improved.

[litesong]

Originally Posted by deluxx

Isnt the bigger tire giving you worse MPG for stops and starts? Is this a strictly highway vehicle?

As stated, the taller tires aren't like an extra gear. Theoretically, acceleration is less, but I don't care. I'm more concerned about performance being less in higher mountains. But so far, up to 5500 foot mountain passes, I'm happy. The Accent gets better MPG because of the lower rpms in top, 5th gear. Top gear can be had by 35MPH on flat roads, which makes it ideal for 35-40-45MPH country roads or higher MPH city streets. The slower rotating big tires absorb bumps better & lower rpms, make the Accent feel smoother & "more grownup" at highway speeds, too.

The wide tires make cornering very sure & safe! But as said, corner slowly, so suspension stress does NOT increase. Of course, if you use narrow AND TALL tires (a thread in Ecomodder discusses such), you'll get even better MPG, once in top gear above 35MPH.