Fuel Saving Thread: Motoring Tips & Tricks

[du nuthin]

Obviously a working medium is required for thermal expansion. If it wasn't, then it wouldn't be called thermal expansion. However this is not what you stated. You stated that the energy that provides the expansion of the medium does NOT come from heat which is a false statement.



OmCheeto, I cann't remember exactly where I heard that nor could I find any info on it either. I believe I heard it from a german engineer from my last job. Also, all articles I could find on it were no later than 2006. There seems to be no info on it from the past couple years. So, its anyones guess what stage the project is at now.

I had stated that "it is the volume of combustion gases that drives the piston and not heat. Heat is a by-product of combustion." A Water Diesel Emulsion fuel uses waste heat from the combustion of fuel to convert water into superheated steam. My contention is "Why use pure diesel, when you can get the same performance from a fuel containing only two third fuel and one third water?"

 

[B. Elliott]

One thing I recommend to people if they don't do a lot of long-hauls, is to not fill up completely when they stop to get gas. One gallon of gas weighs ~6.2lbs, +/- .3lbs depending on the temperature. If you drive a vehicle with a large enough gas tank, the weight can really start to add up.

My DD has a 13 gallon gas tank, but I only pump about 4 or 5 gallons when I stop. Granted I have to stop more often, but I usually stop in gas stations frequently for drinks or a snack anyway. In my case, it's saving the car from having to haul around an extra ~56lbs for no reason. I also ditched my spare tire and factory toolkit since I have a cellphone.

 

[LowlyPion]

The thing that would likely help me save is having some kind of feedback on the dash that indicated the actual rate of fuel use, maybe even the amount of fuel use on a trip normalized to cost to make it easier to relate to. That way you end up knowing in concrete terms how much the trip to the grogers cost you fuel-wise.

But I don't see paying a lot for something like that.

I think it would help people see the incremental difference in carrying extra weight or passengers, or slowing to a light from farther back and not coming to a complete stop before a light changes, etc. Basically any feedback that raises consciousness in gas usage seems like a good thing and might pay noticeable benefits in fuel use more universally.

 

[russ_watters]

Some cars have them and yes, they would be a big help. I've heard people say they can watch the gage and learn how to drive more efficiently.

 

[LowlyPion]

Some cars have them and yes, they would be a big help. I've heard people say they can watch the gage and learn how to drive more efficiently.

I'm not a big proponent of making cars more complicated, but it seems that the on board computer that already likely has the necessary access to information like cycles fired, and could additionally get measures of gross pedal detent and self calibrate on learned fuel usage, could with incremental hardware cost and programming be used to provide a fairly accurate instantaneous as well as trip and tank efficiency.

But I think it would need to be integrated by the manufacturer and I can imagine it would be decidedly inaccurate if it was an add-on.

 

[OmCheeto]

I'm not a big proponent of making cars more complicated.

I am. As long as they can be made to function reliably, complexification is not a bad thing.
Just look at your pc. 30 years ago they were dumber than a modern cell phone. PC's are now more complicated and more reliable. (I drive a macbook. 1 crash in 1 year. It's all about manufacturing quality.)

But I didn't resurrect this thread just to argue with you.

Tah dah!

You can now bid on a 150mpg Toyota Prius plug in hybrid on ebay.
It's actually a charitable auction, with proceeds going to pluginamerica.org

Bidding started at $25k on Halloween and is now at $42.1k

I wasn't sure where to put this post, but I figured if someone wanted to get better fuel savings, just buy a car that gets great mileage.

Trying to eek out an extra 20 to 30% fuel economy in a car that started out at 20mpg is just silly. Which is, um, what I've been doing...

 

[russ_watters]

But I think it would need to be integrated by the manufacturer and I can imagine it would be decidedly inaccurate if it was an add-on.

I don't think so: all cars are required by law to have a standard data port for diagnostics. I have a device that data logs mine (I bought it because it was cool and only use it occasionally). It shouldn't be hard to plug into that and add access to your car's inner workings. Heck, don't street racers do that? I'm pretty sure I saw a guy screwing with his motor via a laptop right before a race on "The Fast and the Furious" (yeah, I did just cite that...).

edit: here's a piece of software for that kind of thing (look at the last pic in the article): http://www.thinkythings.org/obdii/

Here you go: http://www.ecutalk.com/consultlcd.aspx
Not real slick looking, but while I was googling, I saw that GM is going to start making an aftermarket display for this. People are also modding pocket pc's and PSPs for this. I'd love to have such a thing mounted on my dash next to my mp3 player and gps.

 

[Mech_Engineer]

I'm not a big proponent of making cars more complicated, but it seems that the on board computer that already likely has the necessary access to information like cycles fired...

But I think it would need to be integrated by the manufacturer and I can imagine it would be decidedly inaccurate if it was an add-on.

Here you go: http://www.ecutalk.com/consultlcd.aspx
Not real slick looking, but while I was googling, I saw that GM is going to start making an aftermarket display for this.

This is what many people I know use: http://www.scangauge.com/. I have a BR3 OBD-II scan tool from these guys http://www.obddiagnostics.com but it requires a laptop to use it.

The Scangauge has a calibration step for mileage that you can use to make sure it's accurate; both units can display many engine metrics that are reported through the OBD-II system like RPM, throttle %, air intake temperature, air intake flow, etc. etc.

It shouldn't be hard to plug into that and add access to your car's inner workings. Heck, don't street racers do that? I'm pretty sure I saw a guy screwing with his motor via a laptop right before a race on "The Fast and the Furious" (yeah, I did just cite that...).

That's a whole new level, and usually is because the engine has aftermarket components that severely change fuel and air delivery, like aftermarket forced induction.

I have a piggyback fuel/timing calibrator (SplitSecond FTC1-E) on my Toyota 4Runner because I have a supercharger and larger fuel injectors on it. Using a laptop I can tune fuel and timing maps that "trick" the engine's stock ECU into adding more or less fuel, or decreasing timing advance to help get rid of spark knock. Installation of the unit is very involved and requires cutting and/or tapping into wires going to the stock ECU (you have to be sure you want to do it).

Each tuning map is basically a spreadsheet with engine rpm and manifold absolute pressure for columns and rows like this: fuel map example. Using a laptop to program the unit, you can adjust how much fuel is being put into the engine at a specific rpm and manifold pressure.

 

[russ_watters]

This is what many people I know use: http://www.scangauge.com/.

Very cool and not too expensive - I think I'm going to pick one up.

 

[Redbelly98]

Trying to eek out an extra 20 to 30% fuel economy in a car that started out at 20mpg is just silly. Which is, um, what I've been doing...

It's not silly. Increasing a 20mpg car by 20% will save about 8 gallons for every 1000 miles driven. (About one month's worth of driving.)

Increasing a 40 mpg car by 20% has less fuel savings, about 4 gallons per 1000 miles.

 

[mheslep]

...You can now bid on a 150mpg Toyota Prius plug in hybrid on ebay.

150 seems inflated. The PHEV Prius modified by google reports ~93mpg avg, 115mpg peak.
http://www.google.org/recharge/experiment/

 

[russ_watters]

150 seems inflated. The PHEV Prius modified by google reports ~93mpg avg, 115mpg peak.
http://www.google.org/recharge/experiment/

It's not inflated, it's just that "fuel economy" is a completely meaningless concept when talking about plug-in hybrids. If you take a short trip and never need to turn on the engine, the "fuel economy" would be infinite. If you take a long trip and run on the engine for 90% of it, the fuel economy will be more like 35-40 mpg.

There are federal standards for fuel economy ratings, but they probably have not been updated to cover plug-in hybrids and electrics. They need to be. For pure electric vehicles, you need range and miles per kWh(a direct replacement for mpg that could even use the same test) under city and highway driving. For plug-in hybrids, you need the same thing, plus and city and highway mpg for pure engine operation.

 

[OmCheeto]

It's not inflated, it's just that "fuel economy" is a completely meaningless concept when talking about plug-in hybrids. If you take a short trip and never need to turn on the engine, the "fuel economy" would be infinite. If you take a long trip and run on the engine for 90% of it, the fuel economy will be more like 35-40 mpg.

There are federal standards for fuel economy ratings, but they probably have not been updated to cover plug-in hybrids and electrics. They need to be. For pure electric vehicles, you need range and miles per kWh(a direct replacement for mpg that could even use the same test) under city and highway driving. For plug-in hybrids, you need the same thing, plus and city and highway mpg for pure engine operation.

Since the graph and statement appear to have been generated by the company which performed the modifications to the Prius, I'd say there is room for suspicion.

EPA Urban Dynamometer Driving Schedule (UDDS) Test Results Show 150+ MPG with L5 PCM​

They don't appear to include the energy of the battery pack in the calculations.
At 5kwh rated, it would have expended about 50 cents worth of energy over the 29.4 miles of the test. The general rule is to convert the value of the electricity into equivalent petrol costs. At $2.50/gal, this equates to 1/5 gallon. Which over 29.4 miles yields 147 mpg.

When combined with the mpg of the gas engine, we get about 75 mpg.

Still, not bad.

 

[russ_watters]

Isn't "L5 PCM" the battery capacity?? The way I read the situation is:

What a Prius mod seems to do is change the formula for mixing the battery and gas power, allowing the battery to run down further than it would under normal hybrid mode. But since the Prius wasn't designed from the ground-up to be a plug-in hybrid, it just doesn't have the range on pure battery power to run for very long. So they run with both - just with less engine than in normal hybrid mode. This gives it what appears to be about 25 mi before exhausting the battery.

It would be beneficial for a consumer to actually be able to adjust the gas/electric mix based on their commute. If they only drive 20 miles, they aren't getting the best "fuel economy" they could because they could be runnig more on battery. If they drive more than 30, they also get hurt by not having any battery power left to help accelerate - basically losing the entire main benefit of a hybrid.

 

[mgb_phys]

Even running on batteries the Prius will occasionally run the engine - I think this is to keep the cat at the correct temperature.
The prius we had at work wasn't particularly impressive - overall mileage was worse than a European sub-compact, their excuse was that it was tuned to meet emissions specs in california which only counted the emissions when it was running on gas, not the overall average.

 

[OmCheeto]

Isn't "L5 PCM" the battery capacity??

I can't keep up with acronym's anymore. Everyone seems to be speaking in them.

It would be beneficial for a consumer to actually be able to adjust the gas/electric mix based on their commute.

That's exactly how I would do it.

A 3 mode switch on the dash with little symbols for the driving situation:

: pure electric(good for dashes to the corner store, stuck in rush hour traffic, going down hills, Sunday driving): 150 mpg equivalent
: can't tell it from a pure gas fueled car(dynamic, uncertain situations): 75 mpg equivalent
: 1/4 mile dragster mode(getting on the freeway, eluding the cops, testosterone overloads): 25 mpg equivalent

The electric sections have the advantage of putting energy back into the battery pack.
Until we can figure out how to convert CO₂ and H₂O back into methane on the fly, ICE's are on my poop list.

Even running on batteries the Prius will occasionally run the engine - I think this is to keep the cat at the correct temperature.
The prius we had at work wasn't particularly impressive - overall mileage was worse than a European sub-compact, their excuse was that it was tuned to meet emissions specs in california which only counted the emissions when it was running on gas, not the overall average.

I'd say company cars would be the worst example of potential for gas mileage. I've driven with my companies couriers. If they're not paying for the gas, it's mode all day long.

I'll see if I can't get the mpg numbers from our "fleet services" department.

 

[Topher925]

The prius we had at work wasn't particularly impressive - overall mileage was worse than a European sub-compact,

You comparing apples and pumpkins. The prius is not a subcompact and is actually a fairly good sized car. Most of those 50+mpg European cars can't even hold a bag of golf clubs let alone comfortably sit 4 people.

 

[mgb_phys]

Oh I agree - it was more that 'hybrid' doesn't automatically mean super fuel economy.
A small car VW Lupo, Nissan Micra with a 1.2litre diesel will do 70mpg for a fraction of the cost.

Even in city driving VW's approach of leaving out the batteries and having a small diesel engine that can start almost instantly and so turns off if you are stationary for more than a few seconds is possibly a better aproach.

 

[brewnog]

There are federal standards for fuel economy ratings, but they probably have not been updated to cover plug-in hybrids and electrics. They need to be.

A recent article I read (I forget where, possibly The Engineer) interviewed two or three chief engineers working on hybrids. This was the primary complaint from all of them, and all their respective companies are currently lobbying governments to address this issue.

I'll try and find the article at work tomorrow, you'd find it good reading.

 

[mgb_phys]

There are federal standards for fuel economy ratings, but they probably have not been updated to cover plug-in hybrids and electrics.

They also need to be adjusted both ways - a lot of places have tax incentives for hybrids without considering how green they really are:
So Mercedes now have a hybrid option for their s400 luxury salon - it's a 300hp V6 gasoline with an 20hp electric motor, in case your CEO needs to reduce your CO2 emissions.

Our safety team has a hybrid Ford truck that is completely useless. If you go above 5mph or turn on the AC it starts the gas engine to provide enough power - the batteries can just about run the electric windows. I think the logic was, environment is good, safety is good therefore the safety guys must have a green vehicle!

 

[Topher925]

So Mercedes now have a hybrid option for their s400 luxury salon - it's a 300hp V6 gasoline with an 20hp electric motor, in case your CEO needs to reduce your CO2 emissions.

They probably have AA's powering the electric motor too. Sadly there is a lot be bureaucracy that comes with "going green". A lot of people spend money on crap like that just so they can think they are trendy and are making a difference. If you really want to save some fuel, then ride your bike like me.

 

[mgb_phys]

The UK introduced company car taxes based on the CO2 emission to discourage huge luxury company cars (or to tax the poor oppressed CEOs depending on you POV).
I'm betting Merc has found a loophole somewhere that you don't pay tax on hybrid company cars.

 

[baywax]

Side lights are compulsory over here.
Strangley my car turns them off when you put the handbrake on - even if the engine is running. It's a manual and I learned in the UK so I put the brake on like a good little safe driver everytime I stop.

Having a manual here is a great anti-theft device - people steal your car and drive off in first gear. It also means you don't have all that safety interlock crap where you can only start of the seatbelt is on, car is in neutral, feet are on the brake and you whistle the "star spangled banner" three times.

Hee hee. I dig standard for all those reasons and more... its also more gas efficient. However, you can't do cruise control which is highway gas efficient.

Yah, my solution is the Extreme Miser Driving School of Hard Knocks. This includes coasting up to red lights or... if on a hill... not accelerating. It also means coasting with no acceleration down hill. And never exceeding 50k (30mph) where posted since it is optimum (so we're told) for fuel saving measures. This gets the aggressors more aggressive so... in the long run and looking at the whole... perhaps it doesn't save gas because it gives the aggressive driver a reason to gun it!

 

[baywax]

Let's get drastic. Electric cars will save lots of gas. The first city in North America to allow completely electric cars on its streets was Oak Bay just outside of Victoria BC in Canada. The next is Vancouver. We have electric truck and car manufacturers on the Island and Mainland who are doing better and better these days. Their getting some major speed out of these things and distances of about 180 k (kilometres). This is mostly for fleet vehicles mind you. There are some fuel cell fleet vehicles trolling around as well out of Vanc.

 

[brewnog]

Hee hee. I dig standard for all those reasons and more... its also more gas efficient. However, you can't do cruise control which is highway gas efficient.

Hmm, my manual has cruise control...

 

[FredGarvin]

My manual has cruise too.

 

[turbo]

So does my wife's Subaru Legacy, and unless the terrain is very hilly, that little sucker stays right on target within a mph or 2.

 

[baywax]

Hmm, my manual has cruise control...

I had no idea. Well, it is Canada.

 

[Topher925]

I had no idea. Well, it is Canada.

Well that says it all right there.

 

[mheslep]

Let's get drastic. Electric cars will save lots of gas. The first city in North America to allow completely electric cars on its streets was Oak Bay just outside of Victoria BC in Canada. The next is Vancouver. We have electric truck and car manufacturers on the Island and Mainland who are doing better and better these days. Their getting some major speed out of these things and distances of about 180 k (kilometres). ...

Great! You buy the first round though.

 

[baywax]

Great! You buy the first round though.

They are actually converting Ford F150s and the like.

Here are some manufactured from the ground up in Quebec (home of Bombardier)

http://www.zenncars.com/

Here's the Vancouver Electric Vehicle Association.

http://www.veva.bc.ca/home/index.php

Here's the full story about "Electric-car conversion alive on Vancouver Island"

http://www.canada.com/vancouversun/news/driving/story.html?id=e0190a0b-62d6-4d09-8eb7-0ac67ae8547d

He started out converting S10s (?) and now will convert any car as long as its lighter in weight. Looks like he got some of his inspiration from the State of Arnold (California).

But, I'll buy the first round!

Anyone ignoring or frightened by the prospect of getting off gas as a propellant is going to miss out on the multitude of new opportunities that will inevitably sweep the world. The same way gasoline exploded as an economic engine, sustainable electricity will be the next wave. Would Cold Fusion help in some way in this project? If so, can it actually happen?

 

[OmCheeto]

Anyone ignoring or frightened by the prospect of getting off gas as a propellant is going to miss out on the multitude of new opportunities that will inevitably sweep the world.

I'm not afraid.

I built an electric boat this year.

hmm... well, not totally unafraid...

I only invested $80...

And 70 of that was for that battery that I didn't pull out of my chia-boat.

 

[mgb_phys]

Vancouver just chnaged the rules it allowed light electric vehicles on roads where the speed limit was <40kmh - it just raised that to 50km/h (ie 30mph) to encourage them. Unfortunately there are a lot of bridges in Vancouver and the speed limit on all of them is 60km/h - so you can have an electric vehicle here, you just can't get it in or out of the city. (you can ride 50km/h limited gas powered scooters on the bridges)

 

[baywax]

I'm not afraid.

I built an electric boat this year.

hmm... well, not totally unafraid...

I only invested $80...

And 70 of that was for that battery that I didn't pull out of my chia-boat.

Whoa cool!

Solar panels instead of sails!

 

[baywax]

Vancouver just chnaged the rules it allowed light electric vehicles on roads where the speed limit was <40kmh - it just raised that to 50km/h (ie 30mph) to encourage them. Unfortunately there are a lot of bridges in Vancouver and the speed limit on all of them is 60km/h - so you can have an electric vehicle here, you just can't get it in or out of the city. (you can ride 50km/h limited gas powered scooters on the bridges)

That's true. Tons of bridges. Officially it would be a traffic violation. Unofficially there are scooters, electric scooters and Honda Passports on them all the time that don't do more than 40 kmph.

Sorry for side-railing the topic. This is supposed to be about saving fuel, not eliminating it from the diet. There's probably a while to go on gas before plugging into electricland.

Have U.S. car makers been aware of a way to manufacture highly efficient engines, yet have been held back from this practice by their main supplier of fuel, the oil industry? There's always rumours about that. How would one find out? Freedom of info?