Do you hypermile

[RaceDiagnostics]

I see a few people saying its too boring to do but there is nothing more boring than being stuck in the same 23 mile, 1hour commute day in day out. For me hypermiling releives the monotony and makes virtually no difference to the commute time.

 

[Crater Creator]

Diesels don't have a throttle. On the overun, they're just an air pump. Add in the restrictions in the exhaust (cat, dpf) and higher rpm generally means more work being done. The lower your rpm, the less air volume you have to pump per minute through a restricted pipe.

I don't know the intricacies of the speed awareness course but am guessing that pointing out the teacher is wrong isn't the best plan. I was thinking dumb, solemn compliance regardless of how daft it is will get proceedings over with the minimum of fuss and hassle. I'll find out soon enough.

I was assuming Lufbramatt was referring to petrol, due to the set air-fuel ratio comment.
You're right about the diesel - but newer ones do have a butterfly valve in the inlet, maybe not a throttle, but does create an inlet manifold vacuum under some conditions (to help the EGR work apparently). Not arguing, as what you say is right, but I was just thinking that I have just changed out the throttle body on my diesel Iveco so I know it does have one... I would be very happy and a few quid better off if it didn't though.

 

[Shox Dr]

I see a few people saying its too boring to do but there is nothing more boring than being stuck in the same 23 mile, 1hour commute day in day out. For me hypermiling releives the monotony and makes virtually no difference to the commute time.

While I dont 'hypemile' I try and anticipate what is likely to happen, that way you dont need to use your brakes, unless coming to a stop.

We've just been to Scotland and back in my sons new Audi S3 (autobox). So M62>A1>A66>M6>A75...

(I drove) The subject of using cruise control came up, he uses it I dont; reason [I believe] you end up braking more. So we counted the times I braked, and from home [once on mway] to the A75 I braked twice at scotch corner and once at the A66/M6 roundabout. Speed well lets just say I was making good progress.

My son drove the same road back using CC [set at 74mph] we lost count. He also used more fuel.

 

[Tinbasherdan]

I spent a few days with Dave Walker while he dynoed/mapped some silly engines for me using one of his Emerald cams programmable ecu`s. The fuelling map from 7000rpm down to 1000rpm on a released throttle has no numbers dialed in, so no fuel injects until the engine hits 1000rp on a released throttle. Fuel consumption in this case was not the issue but more for engine braking , that said there is no sense mapping unwanted fuel in on so the two would go hand in hand.

Bob

Beast

Will you stop it with the toys man, I'm coming over all funny.


Also, no matter how I drive it, no matter what I'm pulling my old bag of crap will consistently give me 25-27mpg, and the bike, well no one buys a bike to go slow

 

[dobbslc]

I don't think I've ever worked out the mpg on any of my bikes! They are all better than a car and definitely better than my 4X4......

 

[Crater Creator]

I don't think I've ever worked out the mpg on any of my bikes! They are all better than a car and definitely better than my 4X4......

My old ZZR1100 was great on petrol - 50+ mpg at a steady 90 on the autobahn for hours on end. If I went faster or slower than 90 I used more petrol, it seemed to just have a sweet spot there.

 

[zx9]

I don't think I've ever worked out the mpg on any of my bikes! They are all better than a car and definitely better than my 4X4......

When I had the GPZ1100 with a 1170 kit and smooth bores I could get it down to under 10 MPG, back then I was young, foolish and speed cameras had not yet been invented.

 

[mr migwire]

coasting iirc is an offence and can get you into trouble if your caught by having an accident

I don't think I've ever worked out the mpg on any of my bikes! They are all better than a car and definitely better than my 4X4......

i shudder to think what i get from my ZX6 but with it being tuned and having a rather shouty exhaust i can bet it aint much.

 

[Tinbasherdan]

coasting iirc is an offence and can get you into trouble if your caught by having an accident

i shudder to think what i get from my ZX6 but with it being tuned and having a rather shouty exhaust i can bet it aint much.

Pretty sure I've had the r1 down to low doubles and possibly even single figures when really hoofing along.on a track of course.

 

[Justme]

The lady conducting my speed awareness course told us it's a good idea to use the gear that matched the speed limit, 2nd in a 20mph zone, 3rd in a 30 zone and so on.

Of course someone said 'That'll use loads of fuel, my husband won't allow it'.

The lady said all fuel injected cars are made to be driven like that, the ecu will adjust the fueling to the need and mpg will stay the same.

Can anyone familiar with these things confirm this?

I find the trick does work very well if I can remember to do it, anyway whats a little fuel if it stops point and fines..

On my car there is a large overlap between each gear where it does not matter if you are in the higher gear or the lower one.

A high gear but having to use a lot of gas pedal to maintain speed is worse than a lower gear with a higher RPM but lower gas pedal input. Each engine will have a sweet spot that it is tuned to be the most efficient at.

 

[Justme]

We've just been to Scotland and back in my sons new Audi S3 (autobox). So M62>A1>A66>M6>A75...

(I drove) The subject of using cruise control came up, he uses it I dont; reason [I believe] you end up braking more. So we counted the times I braked, and from home [once on mway] to the A75 I braked twice at scotch corner and once at the A66/M6 roundabout. Speed well lets just say I was making good progress.

My son drove the same road back using CC [set at 74mph] we lost count. He also used more fuel.

That says more about your driving ability compared to his than cruise control.

I use cruise a lot but not just in a set & forget way. I am looking far ahead & will add or remove speed in 1mph increments depending on what is going to be happening in the future. Set & forget holds speed up a hill whilst a driver might allow it to slow a little & regain it on the down hill.

On cruise you have to be more aware of what is happening than when driving manually.

Manually you can just lift off the gas to slow a little on cruise if you are not incrementing it you have to brake to reduce speed.

 

[Justme]

My 24 year old Volvo has a fuel economiser option (not fitted to my vehicle). It's a black box which takes vehicle speed and engine rpm and puts a light on to tell you to change up. There is a clutch switch, presumably to cancel the warning light when the gear change is made.

I don't see why modern cars shouldn't have a clutch switch to keep the engine running when you take your foot off the gas to change gear.

Mine does. It has two clutch switches one at the top & one at the bottom.

It uses them for cruise & hill start assist functions. Plus on gear changes lots of modern cars will hold the revs up for a short while like us older drivers had to do when changing / matching gears with crap or no syncro's.

 

[Justme]

Shes talking nonsense

The ECU aims to maintain a set air-fuel ratio, in a lower gear the engine is turning faster and sucks in more air. So you have to stick more fuel in to compensate.

If the ratio was maintained you would not be able to accelerate.

Engine cant suck more fuel as its ruining at a fixed rpm till more fuel causes an increase in RPM that increases air in then more fuel then more rpm then more air etc.

Thats how the carbs used to work, an extra injection of fuel to start the rpm increase or the rpm would lower when the butterfly valve opened.

A high load needs a richer mixture than a low load.

 

[RaceDiagnostics]

On my car there is a large overlap between each gear where it does not matter if you are in the higher gear or the lower one.

A high gear but having to use a lot of gas pedal to maintain speed is worse than a lower gear with a higher RPM but lower gas pedal input..

Not on my car, the manual says the opposite, get into a high gear as soon as possible, skipping gear changes if possible. The dash board recommends gear changes, much sooner than anticipated and even leaves the engine sounding like its laboring, all with the goal for better MPG.

The issue is the faster the engine is spinning the worse the frictional losses are.

 

[wookie]

I think I'm going to test this theory, if the fuel is totally shut off turning the ignition off will make no difference what so ever if however a difference is detected then it must still be fueling the engine

Well snooper I tried turning the ignition off whilst driving down a slight hill with my foot off the throttle, I couldn't detect any difference at all which reinforces my belief that on the overrun the ecu doesn't inject any fuel.

 

[the snooper]

Well snooper I tried turning the ignition off whilst driving down a slight hill with my foot off the throttle, I couldn't detect any difference at all which reinforces my belief that on the overrun the ecu doesn't inject any fuel.

hmm diesel or petrol

 

[the snooper]

i dont know abot hypermile, we will all be hyperventilating if the cost of fuel keeps rising

 

[wookie]

hmm diesel or petrol

Diesel, Peugeot 306 2litre HDI

i dont know abot hypermile, we will all be hyperventilating if the cost of fuel keeps rising

It made me laugh the other day when all the rail commuters where on the news complaining about the fares going up, they should try driving instead, historically petrol & diesel have gone up way more than rail fares.

 

[Gareth J]

Diesel, Peugeot 306 2litre HDI

It made me laugh the other day when all the rail commuters where on the news complaining about the fares going up, they should try driving instead, historically petrol & diesel have gone up way more than rail fares.

If you take out inflation, petrol prices have remained pretty stable overall. Various global craziness causes spikes but prices tend to drop back to a "norm" of about what were paying now.
https://www.statslife.org.uk/econom...-mean-the-historical-cost-of-filling-the-tank

That's a bit old now, but you get the picture.

It would be interesting to see how rail costs compare. Harder to make a direct comparison I guess as tickets prices vary wildly.

 

[the snooper]

Diesel, Peugeot 306 2litre HDI

It made me laugh the other day when all the rail commuters where on the news complaining about the fares going up, they should try driving instead, historically petrol & diesel have gone up way more than rail fares.

only problem with driving is parking and the costs associated with it which makes driving even more expensive then there are maintenance, tax, mot & insurance costs to add to it