Hypermiling videos to better fuel consumption

[puntmeister]

I highly recommend the link given by Jagerbecher. Thanks again.

There are posters on it who are much more knowledgeable than I am about all of this, and have done a good job of explaining how the BSFC does, and does not, apply to MPG.

Another quote:

"The ALH engine installed in MK4 TDIs is a prime example. To achieve best (i.e. lowest) fuel consumption you should be operating in the range of 1,250 to 1,700 rpm at all times."

 

[puntmeister]

Not exactly the most scientific explanation, but its along the lines of an example I was thinking of:

"You can use less energy to overcome inertia if you do it slowly. What would make you more tired: pulling a heavy wagon slowly from a stop to an all-out run, or pulling the same wagon immediately to a sprint? Pulling the wagon slowly lets you build momentum to help overcome inertia, using less energy. In your car, you should accelerate slowly from stops, allowing the car's momentum to help it accelerate."

Pulled from "Top 10 Green Driving Tips" on HowStuffWorks

I'll try to drum up more definitive evidence...

 

[puntmeister]

Meanwhile, the three letters most of us manual drivers, who insist we drive manuals cuz they get better MPG than automatics, have to fear most: C....V....T

If you take a look at the line-up of cars which offer CVT transmissions, the CVT versions actually get better MPG than the manual versions.

It stands to reason - CVT transmissions offer a continuous transfer of engine-output to propulsion - there is no clutching/shifting of gears as with manuals/geared automatics.

I often why CVT wasn't offered on cars, when it has long since been a common feature of scooters....

Turns out, there was in issue applying CVT to high-torque engines (obviously not a problem with 50cc scooters).

 

[puntmeister]

To boot - CVT transmissions are actually very simple in design - much simpler than geared automatics and, quite frankly, simpler than manual transmissions as well.

They are likely to be highly reliable and, in the event of a failure, more likely to be repairable by a DIYer than either manual or automatic transmissions.

Basically, they win hands down. I can see a day in the future where all cars are CVT, and manual is not even an option any more. Which blows, cuz I like shifting.

 

[Jagerbecher]

I see the point that puntmeister is trying to make about acceleration. While BSFC chart relates to an isolated engine (let's say engine on a testbed or dyno) or the engine in stationary application, it may not mean that other physical factors that affects whole car during acceleration do not offset the engine efficiency during hard acceleration. To know the answer someone would need to calculate or experiment. But several forum members reported that according to their observation and VCDS the harder acceleration resulted better fuel economy. And I can believe that because if I just imagine "neverending" acceleration (let's say from 0 to 60 in 5 minutes, I know extreme example) I can't see how it could be more efficient then acceleration during which the rpm is kept in highest torque range.

 

[Lmannyr]

For what it's worth....

Going by MFD...

Cruising at 55-60mph on florida I-95 gives me 60mpg.

P&G between 50-60 gave me 85mpg for the last two days.

Same route, same distance (65 miles), Same times.

I'll hand calculate at end of tank and post back.

 

[rotarykid]

the CVT is not all that in the real world....

It is not as simple as you assume, No where near as simple as your writing show you believe..........

The CVT is heavy because of the materials needed to make it work. It is a really complex build design along with needing expensive materials so it doesn't eat it self when in use. And It's really expensive to build compared to slushboxes, even the current complex offerings. And it is as much as 3 times as much as one of the currently used manual transmissions......

When compared to other transmissions used today. It is heavier than most currently offered slushboxes quite a bit than some. And it can weigh double compared to some manual transmissions. It has some fairly required costly service and repair issues. And long service lives are not the norm on the current offerings of CVTs in higher power applications. There is a lot to be worked out before they become widely used.........

In most current applications the CVTs have a really heavy big chain that is really expensive to replace when it reaches the end of it's service life or when it fails. And they do fail.!.......

When the CVT chain fails it's not just the chain but the guides and many times all of the gears. If the chain breaks it can destroy case making the transmission useless. Costs of repair can exceed the cars value.....

And I haven't even gotten to the real issue, they use more fuel in many conditions than regular high tech slushbox today! And they use a lot more fuel than a manual trans driven by a well trained driver in the real world in all driving situations.......

I have years of real world data on Nissan CVTs used in several the current applications. City used CVT applications used over rolling or hilly terrain pay the highest mpg penalty. I have seen first hand how bad these things can be in city driving..........

In a Nissan Versa side by side manual trans & CVT I have consumption numbers. For same year, same options, driven over similar terrain I have consumption numbers for ~50k miles driven around the Denver region. Records that show the manual trans version is twice as efficient as the CVT in city driving around Denver.

On average in mixed & city driving the Versa a manual trans version is seeing 35-40 mpg to low 40s max and the CVT sees high 10s to low 20s mpgs at best mixed with low 30s highway......

I also have a several of years of records for a Alitma CVT and a manual trans version. And on city loops the difference is over double on most tanks. The manual trans version can achieve on city loops above 30 mpgs, mixed low to mid 30s and all highway high 30s mpgs if speeds are kept down. IF the speeds are high on the highway it can drop to the 26-30 mpgs........

In the CVT Altima the numbers are high 10s to low 20s mpg on city only, mixed high 10s to mid 20s mpgs and on the highway consumption can get close to 25-27 mpgs if speeds are kept low enough. If You push speeds on the highway it can drop to low to mid 20s mpgs....

Now, Nissan claims it has a new design of CVT that is 10-15 % more efficient than the current & previous CVTs. And if those claims are true it will still be 30 % less efficient than a manual trans version...

 

[puntmeister]

Much appreciated post on CVT's - I admittedly am not up on all the details when it comes to CVT. Anything I wrote about CVT was either speculation, or based on the scant data provided by manufacturers (higher MPG numbers, for example, for new CVT versions of cars vs/manuals).

I do realize the drive profile has a significant impact on real-world MPG - everyone on these threads is keenly aware of that .

I find it hard to believe, however, that the MPG figures quoted for new cars are so far off - in the sense that they show CVT as (modestly) better than manual, but you claim they are actually 30% to 50% worse....however skewed the quoted numbers are, they are skewed for both manual and CVT alike, as the testing procedures would be identical. If the testing procedures aren't identical, or the numbers are skewed in some other fashion, then the manufacturers are downright guilty of fraud.

As for longevity & repair costs - pure speculation on my part. What you say does make sense - that the chain is very expensive to replace and, if/when it breaks, causes serious damage. Just the same, I'd hardly consider rebuilds of current slushboxes reasonably priced, and I wouldn't consider them durable/reliable either. CVT vs. geared automatic? A race to the bottom, its sounds like....

 

[rotarykid]

Much appreciated post on CVT's - I admittedly am not up on all the details when it comes to CVT. Anything I wrote about CVT was either speculation, or based on the scant data provided by manufacturers (higher MPG numbers, for example, for new CVT versions of cars vs/manuals).

I do realize the drive profile has a significant impact on real-world MPG - everyone on these threads is keenly aware of that .

I find it hard to believe, however, that the MPG figures quoted for new cars are so far off - in the sense that they show CVT as (modestly) better than manual, but you claim they are actually 30% to 50% worse....however skewed the quoted numbers are, they are skewed for both manual and CVT alike, as the testing procedures would be identical. If the testing procedures aren't identical, or the numbers are skewed in some other fashion, then the manufacturers are downright guilty of fraud.

As for longevity & repair costs - pure speculation on my part. What you say does make sense - that the chain is very expensive to replace and, if/when it breaks, causes serious damage. Just the same, I'd hardly consider rebuilds of current slushboxes reasonably priced, and I wouldn't consider them durable/reliable either. CVT vs. geared automatic? A race to the bottom, its sounds like....

Maybe I wasn't clear, but there are some conditions where a CVT is more efficient than a slushbox and can come close to a manuals numbers. Those conditions are over mixed route tanks over flat or almost flat terrain. There is a point when terrain becomes varied enough that those numbers flip in favor of the slushbox.

The current test procedure doesn't really give a clear picture but numbers clocked in the real world do....

The jury is somewhat in on the geared automatics, they are long lived and reliable if proper maintenance is carried out. And if issues that arise are quickly dealt with before catastrophic damage is suffered they can have similar life spans to a manual......

 

[puntmeister]

rotary,

Gotcha.

Yes, I suppose its true, current automatics can be reliable, if properly maintained - I just know of so many instances of automatics going bad. Then again, that's probably because most people never bother to change the trans fluid/filters.

To be fair, clutches go bad often too (mainly due to bad shifting methods) - but, its generally much cheaper to change a clutch, than rebuild an auto trans.

In any event, even if the quoted MPGs of CVTs were representative of likely real-world driving, and did get consistently slightly better MPGs than manuals, I would still choose to drive a manual....

 

[SD26]

Some pages back, there was a discussion on how "quick" one should get up to speed, up to fifth gear...all really depends upon where you need to be...35MPH or 55MPH.

Someone stated that they were using the LOD gauge on their Scangauge to "temper" their acceleration...my word, temper. I hadn't used the LOD gauge mode, but I turned it on to see how I was personally performing. And my acceleration was in the 80 range...I believe that LOD is basically the ECM stating what load the driver is asking from the engine given the particular RPM and throttle position. Some things to take note of with that...one can input less than 100% throttle input and that will produce 100% engine load at some engine and ground speeds.

So, back to real world... I found that in my light-ish acceleration and lower RPM shift points, I could produce pretty good MPG. Around 50MPG on my route to and from work. Using the LOD gauge, I found that often I was producing LOD in the 80 to 85 range to get myself up to speed. Not a jack rabbit at all, but it was lightly spirited.

Anyway, some pages back, someone made a statement, or maybe it was another thread even, that one should try to accelerate in the 60-70 LOD range. I think those guys that got 80MPG in the Passat used a Scangauge while driving, and this might have been one of their techniques. I think that they would try to not exceed 70% on LOD even going up long hills, which resulted in them slowing down, downshifting, and even turning on their hazzard lights.

I tried using the LOD gauge reduce my input to that 60-70 range, and I was rewarded pretty consistently with better MPG. My average increased, and my best increased. It certainly makes it to where I'm not going to be the one someone in a rush wants to be behind leaving a stop light and increasing speed to 45MPH. And if one wants to try and use that guide on the Interestate, you might certainly find that you won't always be traveling at the posted speed of 65-70MPH.

 

[pellapat]

today,

24 mile round trip, full tank of gas 59.7

3 kids, 2400 miles on car 35 psi

 

[chrstian2170]

Amazing Economy

I got the car 5 days ago and am getting 55 to 57 MPG. Anybody else see numbers like this? It's most highway driving.

 

[Jetta_Pilot]

today,
24 mile round trip, full tank of gas 59.7
3 kids, 2400 miles on car 35 psi

I do realize this is a very old post!

A full tank of GAS ??????

 

[katahdinTDI]

I got the car 5 days ago and am getting 55 to 57 MPG. Anybody else see numbers like this? It's most highway driving.

I've had a few fill-ups break the 55 mpg mark.

 

[Blue_Hen_TDI]

I got the car 5 days ago and am getting 55 to 57 MPG. Anybody else see numbers like this? It's most highway driving.

They are certainly capable of that. I too have a 2015 Sportwagen, and my best tank was 62.6 mpg (hand-calculated, not the car's highly-optimistic display). You can see all of my fill-ups in my clickable Fuelly signature.

 

[ranger pete]

Read the first few, then last few pages of this thread. Will read the rest later.

Some good info, but I do have a nit or two to pick.

It was said that coasting is always more efficient than engine braking. I disagree slightly.

Coasting in neutral uses fuel. Not much, but some. engine braking, in general, uses none.

Therefore if you have any need at all for deceleration leave it in gear.

I have a lot of experience hypermiling manual gassers and I would generally use engine off coasting when possible, bump starting when power was needed.

I am guessing that this might not be a wise idea with a newer TDI due to the emission system. I read somewhere that these things like long drives and that frequent very short drives will wreak havoc with the emission system as it is interrupted while running through its cycle.

EOCing is simulating short drives, so should I avoid it? Or maybe only do it when I can benefit from very long coasts?

I also wonder about using P&G. It is a no brainer for gassers as you always want to be in the full load sweet spot. But diesels don't have this sweet spot, to the best of my knowledge, or do they?

 

[Mako]

Read the first few, then last few pages of this thread. Will read the rest later.
I have a lot of experience hypermiling manual gassers and I would generally use engine off coasting when possible, bump starting when power was needed.

Diesels don't have throttle plates and a high vacuum induction path at low loads (small throttle openings) which is the primary reason for P&G in a gasser

 

[Webbie1]

To boot - CVT transmissions are actually very simple in design - much simpler than geared automatics and, quite frankly, simpler than manual transmissions as well.

They are likely to be highly reliable and, in the event of a failure, more likely to be repairable by a DIYer than either manual or automatic transmissions.

Basically, they win hands down. I can see a day in the future where all cars are CVT, and manual is not even an option any more. Which blows, cuz I like shifting.

The CVT vehicles that I have driven (rental cars mostly) have led me to the conclusion that I NEVER want one. It's a horrible driving experience. On top of that, do you know of any shops that actually service them? The info that I have, which may be dated, indicated that nobody was actually rebuilding them, but it was a very expensive replacement when something broke on them. I wouldn't own one just based on the miserable driving experience, but the replacement cost on them doubles down on that thought. As usual, opinions vary.

Warner

 

[rotarykid]

the cvt is very heavy compared slush-boxes and ridiculously heavy compared to any manual.....

they are expensive to repair if they can be fixed without a total replacement compared to a slushbox, and they do fail!....that chain stretches, just like all chains do!.....

that chain that runs back & forth is heavy and very expensive to replace along with the other parts required to fix it when it stretches &/or breaks.....

when that chain goes bad most of the time the CVT eats itself to point most of the time rendering the CVT to be serviceable.....

I know from first hand observations of a nissan car that had one that got far worse mpgs in city driving than a slushbox car over similar city only driving....

today most automakers have decided cvt transmissions do not make sense compared to current multi-speed slushbox(6,7,8,9 speeds , ect...) in their offerings in reliability and real world mpgs...

I have no intention of ever owning a vehicle with one of the current pieces of junk current CVT offerings....

 

[johnsTDI]

on my Canadian 2012 TDI i get around 4.5 - 5.2 Liters per every 100km's and that"s using "cruise control set at 115 km's early morning i hit no traffic." so when converted over in u.s.a miles im ruffly getting around 47-50 MPG. Just wondering if leaving cruise control on is best for fuel econo? or turning it off and feathering the gas pedal be better.??

 

[mr_y82]

the cvt is very heavy compared slush-boxes and ridiculously heavy compared to any manual.....
they are expensive to repair if they can be fixed without a total replacement compared to a slushbox, and they do fail!....that chain stretches, just like all chains do!.....
that chain that runs back & forth is heavy and very expensive to replace along with the other parts required to fix it when it stretches &/or breaks.....
when that chain goes bad most of the time the CVT eats itself to point most of the time rendering the CVT to be serviceable.....
I know from first hand observations of a nissan car that had one that got far worse mpgs in city driving than a slushbox car over similar city only driving....
today most automakers have decided cvt transmissions do not make sense compared to current multi-speed slushbox(6,7,8,9 speeds , ect...) in their offerings in reliability and real world mpgs...
I have no intention of ever owning a vehicle with one of the current pieces of junk current CVT offerings....

Well said...

We have a 2011 Legacy with CVT... we are getting about 26mpgs (and it is not like we drive it like a sports car)... They have been problematic for a lot of people (TSBs, but we are holding out for a recall for some sub pars parts). Anyway, my 2001 AWD e46 (BMW 325xi) gets abut 27mpgs with my heavy foot (albeit it always get premium fuel, and has to for the tune...)... They are both 2.5s but the Bimmer has 2 extra cylinders and is faster (weights are comparable due to the BMW being AWD)... So, I have trouble buying that CVTs are 15% more efficient in the real world.

 

[Lightflyer1]

on my Canadian 2012 TDI i get around 4.5 - 5.2 Liters per every 100km's and that"s using "cruise control set at 115 km's early morning i hit no traffic." so when converted over in u.s.a miles im ruffly getting around 47-50 MPG. Just wondering if leaving cruise control on is best for fuel econo? or turning it off and feathering the gas pedal be better.??

If you know what you are doing, cruise control isn't the best. If you were on completely level ground with no traffic at all then maybe. Look up pulse and glide as a technique. I have read of those who have used it properly and it seems to work better, but requires constant attention to detail. It would seem to be hard to keep up for any great length of time though. Can be a detriment in traffic if used. My opinion only.

 

[johnsTDI]

If you know what you are doing, cruise control isn't the best. If you were on completely level ground with no traffic at all then maybe. Look up pulse and glide as a technique. I have read of those who have used it properly and it seems to work better, but requires constant attention to detail. It would seem to be hard to keep up for any great length of time though. Can be a detriment in traffic if used. My opinion only.

at 3:00am in the mornining way before rush hour hits i dont care im setting Cruise Control on the highway and letting it drive me
i see awesome fuel mileage numbers in the 47-50 mpg's range alot better than what was originally posted by EPA.?

 

[Lightflyer1]

Why did you ask then? I just answered your question about is cruise control the best for economy. Use it or don't, whichever you choose.

 

[Turbiny]

Touran 2004 2.0 140hp DSG 6 speedCity driving during 5/6 days 110km -15 liters ? dashboard shows 1=13,6; 2=8,3
Anyone knows how it calculates 1 and how does 2?
Will measure again