100 Mpg Iq A Crazy Idea ?

[bobkneale]

Anyone any ideas how we could get 100 MPG from an IQ ?

Probably a silly idea and possibly not practical from an engineering or modification V cost payback standpoint however just looking to expand my mind to new potential possibilities.

I am currently sitting at regular 70 MPG at the moment as a normal average MPG

All suggestions (except from those of you who already believe it is impossible) are welcomed !

I expect only those of you with a "truly open mind" to reply to this post.

Positive Regards, Bob.

[s44gtw]

Can you really just use 32 litres of petrol & can you truly say you can travel 490 miles on that?

You can get 100mpg if you can hypermile well enough,

but thats going to need to be 32 litres/7 gallons & cover 700 miles.

(not just 0.5 of a gallon & 50 miles starting up a hill)

and to achieve it easier i would travel at an Ambient Temperature of around 5-10 *oC, on a calm day, Not night time with lights on.

& fit narrower tyres, use a higher tyre pressure,

maybe remove the Wiper Blades, passenger and rear seat and anything else in the car.

george

[sweet-dentist]

Do not fill the gas-tank fully.... less weight.
Everything out of the car with no function...and all the garbage out (cards/maps/tools/umbrella's, the lot).
As George said..al the back-seats and / passenger seat?
Small tires as hard as possible allowed...
Flat hubs on the tyre/wheel/rim-thing......
Airstream...so rear mirrors pulled in / rear spoiler?
Do not go over 50 miles/hour... as the aerodynamics get exponential worse.... flat-fronted-bulldog-face..
Cruise control / steady "lead-free" throttle-foot...
Tape all the air-inlets...close them...
Tape all the openings between metal and plastic parts..
Get rid of antenna..
No airco / no ventilation / no radio / no lights.

Peter

PS At this moment I get 7 liters on 100 kilometers.... according the book, it should read... 4.5 liters on the 100 kilometers..
So at this moment I really do not reach any cheap mileage... LOL

And 7 liters tho 100 kilometers...EQUALS 33,798 miles the gallon... talking about a gussler... ;-)

[s44gtw]

If you only want to go 100 miles on the gallon then only put in 1.5 gallons,

but if you want to do 100 miles average over a distance fill the tank because you do not want to stop for fuel and waste any,with stops to fill up.

Then you want to go at 60 mph., drafting a HGV or Luton Van, or whatever speed it is doing.

but not right up its tail, where they can not see you,

but in the back tow (Eddie), then you use almost no fuel. lift off the throttle and you are in the tow.

You know the right spot because if its raining you need no Wiper Blades.

I can draft at a safe stopping distance and achieve 75 mpg in a 1390cc 180ps Twincharger car easily over a long distance..

I can achieve an actual 80 mpg plus at 50-70 mph in low temperatures, and thats over more than 100 miles..

Under 2,400 rpm and on Supercharger, because over that the Economy drops. (then its Super and Turbo to 3500 rpm)

Using Super Unleaded though.

(2 spare wheels carried, passenger and luggage being carried so not lightened or Wiper Blades etc removed, still a 4 seater car.)

**Normal driving in the same car, not Hypermiling gives 450 miles for 10 gallons, so an average 45mpg.**

In a iQ iMultidrive ts easy to get an indicated 68 mpg,

but is that how many miles you are actually getting from a gallon.?

An iQ is good, but its not the best for giving the choice of economy & performance,

or even acheiving both at the same time and still getting 50 mpg plus.

george

[Cyker]

Put my Yaris' diesel engine in it? :D

[bobkneale]

It's intresting that no one has suggested any engine mods etc yet to improve an IQ MPG.

Perhaps there are non that will ?

[sweet-dentist]

Well.. there's no possible remapping of the cpu.... it's a petrol car.

Remapping is mostly done for more power... that mainly increases the consumption.

Putting in a turbo is possible (about 2000 euro) , but I think the car will drink much more.

What more can one do?

Restricting the air-intake? Putting is an air-filter that is really jammed??? The cpu will deal with it..and the power will go done a lot.....

Hmmm....

Restricting the exhaust pipe... so hardly any exhaustgas could come out the pipe? The cpu will deal with it and will throttle the engine down... Uche Uche...

[bobkneale]

Well, I fully understand all the above points made, and they are all very interesting, however we are assuming that Toyota have designed all aspects of the IQ to maximise MPG which I'm sure is true but:

Could they have done a better job of it in any respect ? and if so, what aspects of the engine or engine design and ancillary aspects and engine control / management could have been designed better ? to get improved MPG ?

I am not at all an expert in this area hence my comments to get those of you that have expertize in these areas "thinking about the possibilities" :

For example I would be prepared to sacrfice a little performance to gain better MPG if that makes any sense ?

I have also noted that possibly a CPU remap may enable better MPG at the loss of a little performance ? IE economy re map rather than one for improving performance.

If the CPU could be re mapped to achieve a little better economy under "certain driving or road conditions" then perhaps a ECU remap that was switchable back to standard dependant upon the change of these road and / or driving conditions ?

Under a steady level speed on level road would you get better economy running on one less cylinder ? a reduction in power that may not be noticed under certain circumstances ?

Also as perhaps a seperate issue there is the possibility of engine mods that are similar to Fords latest "Eco Boost" technology however that may be major surgery to achieve and high risk with a lot of R + D to get it right ?

One thing that is noticeable about all combustion engines is that a lot of energy is wasted into waste heat generation that is just taken from the engine and sent into the atmosphere is that not a waste of energy ? and if so how could it better be captured and perhaps used better ?

Then of course there are "all the Gizmos" that are advertized like magnets on the fuel line, cyclones in the are intake, fuel additives and many many more that all have been tested and proven to be scams ! Is that totaly true in every single case ?

Perhaps my above "brainstorm" of above discussion points can all be dismissed by the experts ? I am not an expert just planting some

"Seeds for Thought"

Also I am quite prepared to accept that no more is "practicaly possible" without a complete re design, I just have a "seeking feeling" that

"There Could be More" !

Positive Regards, Bob

[sweet-dentist]

Yes Bob, I agree completely with you about this subject... `your thoughts are well recognized... :-)

One thing I would like changed... is that the CVT has to go quicker in the slower revs... AND stay there... so I can give som gas on a hill...without the cvt starting to yell in the revs... but stays in the low revs and takes more time to accelerate...

With a handshifted car this would mean an "overdrive" on the gearbox... or more gears....

For example the old Smart has a 600 or 700 CC engine with a 6 geared gearbox semiautomatic...

But the new Smart has 1000CC engine and only a 5 geared gearbox... No wonder this car has a worse mileage....

[s44gtw]

Bob,

please let us know when you find a Mapper that can Re-Map the iQ ECU that will stay in the ECU and and can write a map that is going to give increased economy.

george

[bobkneale]

Bob,

please let us know when you find a Mapper that can Re-Map the iQ ECU that will stay in the ECU and and can write a map that is going to give increased economy.

george

I will let you and this forum know know george if I find one !

[Cyker]

Does swapping it for a diesel engine not count as an engine mod then? :D

I don't think there is much in the way of 'easy' engine mods to improve mpg significantly at this stage.

Turbo charging is possible and would indeed recover some of the exhaust heat, but for anything more than light boost you'd need to drop the compression ratio which reduces the baseline efficiency. Or you could go with a high-octane-fuel-only route.

One of the biggest reasons for raised mpg in smaller engines has not been advances in engine tech but advances in materials - Lighter, stronger metals so engine block, crank, pistons etc.

A lot of people think turbos make a car efficient but they don't - They enable a smaller cylinder to burn more fuel than it would naturally be able to; The only reason turbo-charged cars tend to be more efficient is because the engine is smaller and lighter.


There probably is some leeway in adjusting the CVT ratios, but they deliberately run automatics at higher RPMs than you could get away with in a manual to try to reduce the likelyhood of stalling. I don't know what the response time of the CVT system is tho'.

You could redo the valve timings to duplicate the fake-Atkinson cycle the HSDs use which would give quite a hefty boost in mpg, but the engine would probably struggle to get up an incline due to the total lack of torque


Or one easy hack - Stick a block of wood under the accelerator pedal so you can't push it down all the way

[bobkneale]

Does swapping it for a diesel engine not count as an engine mod then? :D

I don't think there is much in the way of 'easy' engine mods to improve mpg significantly at this stage.

Turbo charging is possible and would indeed recover some of the exhaust heat, but for anything more than light boost you'd need to drop the compression ratio which reduces the baseline efficiency. Or you could go with a high-octane-fuel-only route.

One of the biggest reasons for raised mpg in smaller engines has not been advances in engine tech but advances in materials - Lighter, stronger metals so engine block, crank, pistons etc.

A lot of people think turbos make a car efficient but they don't - They enable a smaller cylinder to burn more fuel than it would naturally be able to; The only reason turbo-charged cars tend to be more efficient is because the engine is smaller and lighter.

There probably is some leeway in adjusting the CVT ratios, but they deliberately run automatics at higher RPMs than you could get away with in a manual to try to reduce the likelyhood of stalling. I don't know what the response time of the CVT system is tho'.

You could redo the valve timings to duplicate the fake-Atkinson cycle the HSDs use which would give quite a hefty boost in mpg, but the engine would probably struggle to get up an incline due to the total lack of torque

Or one easy hack - Stick a block of wood under the accelerator pedal so you can't push it down all the way

Hi Cyker, I have not heard of this mod "Atkinson" as mentioned above, what exackly is it ? Just a thought if this mod worked and could become a "switchable" modification ? is this a way forward ?

[johnan]

A moped with a brolly might be the answer?

John

[Cyker]

Hi Cyker, I have not heard of this mod "Atkinson" as mentioned above, what exackly is it ? Just a thought if this mod worked and could become a "switchable" modification ? is this a way forward ?

I was just being a bit flippant TBH

<overly verbose bit>

Basically, the HSD 'fakes' an Atkinson cycle by not closing its intake valves until the cylinder is already moving back up, so it actually pumps some air back out, and doesn't compress a full cylinder of air.

The rest of the cycle continues as normal, which allows the engine to extract a higher percentage of the input energy from the powerstroke as the expansion stroke is longer than the compression stroke. (Longer expansion strokes = more energy extraction; It is why diesels are more efficient than petrols as their higher compression ratio means both the compression and expansion strokes are longer)

The downside is that the amount of input energy is a good chunk less than you would normally get - It's only combusting half a cylinder of air so you only get half the input power to extract energy from; This is why the HSD 1.8L ICE is nowhere near as powerful as a real 1.8VVTi - While it can extract more energy from each L of fuel, it gets a lot less energy per stroke to extract energy from (i.e. 50% of 500 is more than 80% of 200)

</overly verbose bit>

The laborious point is that, in theory, you could alter the cams on a VVTi to do the same late-intake-valve-close to get the same higher energy efficiency, but this would change your fairly efficient 1.0L engine into what is effectively a very efficient 0.5L engine...

Without the grunt of the HSD leccy motor, I think it would be screaming at some insanely high revs all the time just to move off, and it would have to be a CVT because you couldn't fit a 25-speed truck gearbox in an IQ

[Sensha]

While it is not directly applicable to the Euro vehicles you are worrying about, one thing that we have noted about the iQ body form is that the best gas mileage is obtained (given a neutral wind situation and level terrain, something we have quite a bit of here in Texas) at no more than 62 or 63 mph. We have speed limits ranging up to 75 mph here, and we have driven extensive distances at that speed, at 60 mph, and at every speed in between. Anything over 62 mph without a following wind has the miles per gallon drop well down.

If you push the speed up to 80 mph territory, look for fuel economy (with our puny non-Imperial gallons) in the 30 mpg range - or less.

[Cyker]

That's fairly normal; I find most cars have an optimal distance covered vs fuel consumption between 55mpg and 65mph. Even in my Yaris D4D there is a noticeable drop as you get to 70mph vs my normal cruising speed of 63mph (Yay digital dash! :D), although I've been trying 70 lately and it isn't as much as I thought it would be! (It is a lot scarier tho' )

You can design a car to do better at those speeds, but you need low rpm torque and really slippery aero. Maybe something like a diesel-cycle powered Prius Mk3 HSD would do pretty well there as it could run the ICE at probably less than half the RPM the Atkinson lump does and take advantage of the sleek low-drag design.

[Sensha]

From our testing, it appears that the engineers at Toyota designed the iQ platform to have its best fuel efficiency at 100 kph. This may be a common speed limit in Japan (it's been over thirty years since I've been there, and I don't recall a single speed limit at this remove).

We found that setting the speed on the cruise control to the 100 kph point and letting it ride produced the best results, each and every time. Of course, it doesn't get you there as fast as our Texian 75 mph speed limits, but what are you going to do?

[Highridge]

I am interested in this idea, however I shall not be modifying my IQ until the 5 year manufacturers warranty runs out.

I also have 3 free service vouchers left.

Once I get past all that and have to pay for stuff myself there are a few mods I shall be looking into.

1. Evans Waterless Coolant

2. Engine Pre-Heaters

3. Better plugs, HT leads

4. Better Engine and Gearbox oils

5. Ametech Engine Restorer which I used on my old V8s in the past very sucessfully.

6. K & N Air Filter

Not sure if this helps.

[bobkneale]

Hi Karl,

An intresting list in your above post:

1) I cannot see how Evans waterless coolant can improve MPG, perhaps I have missed something ? It reduces the boiling point so less chance of overheating however most people seem to use it in older engines, also a few people have commented that there engine runs hotter and fans kick in more often. Perhaps you can enlighten me ?

2) Engine pre heaters YES on short runs less time getting engine up to temp i guess = MPG improvements

3) Better plugs and HT leads I would not know which ones to buy that are better than original Toyota IQ fitted perhaps you can help me with that one?

4) If I use 100% synthetic oil as Toyota reccomend (IE Mobil 1) is this not the best already ?

5) Ametech engine restorer seems to be for old worn engines ?

6) K & N filter - there are so many different views about these improving MPG and their filtering capability I am not sure ?

So I can 100% see that some of your items listed can help but not sure about all of them re improving MPG

[craggle]

The iQ doesn't have HT leads, it has individual coils sitting directly on the top of each spark plug. The standard plugs are Denso Iridium plugs. I am going to replace mine in the summer but simply because they are now 4 years old. Might go for Denso ones again or NGK Iridiums, probably much the same thing.

Waterless coolants are a good idea, not sure why it took so long to come to the automotive application but to be honest, probably a bit wasted on an iQ as they aren't exactly a high performance machine. I was thinking of using it on my 350ci Chevy powered Cobra though to reduce the chances of corrosion in the block and water pump.

I have a K&N type cotton filter in my iQ. I replaced a very dirty and blocked filter so I did feel a performance increase but a new standard filter would have made a difference too. I like them as you can clean them and re-use them but I'm not too convinced by the increased power claims by the manufacturers.

As for oil additives, I would never touch them. I have seen and had to repair the damage they cause to cars. I have rebuilt a Land Rover gearbox that had Slick 50 added to it and every bearing in that had to replaced. Basically the PTFE coating was so slippery the rollers and balls in the bearings stopped rotating and slid over the bearing surfaces as they were now so slippery. As the effects of the Slick 50 gradually reduced over time this wore flats on each roller or ball so when they tried rotating again, they were bumping around on bearings with two big flats on each ball! That cost a few quid to rebuild.

I have also seen a friction reducer added to a Rover V8 and that coated the flat tappet cam and made it so slippery the lifters stopped rotating as they should and wore flats in the contact face with the cam. This destroyed the cam in a few thousand miles and all the ground off metal debris scored the crank, bores and other bearing surfaces. That was a costly rebuild too.

Just stick to a good quality oil, I use Comma X-Tech fully sythetic 5-30 in my car, Seems to like it and I change it once a year regardless of miles with a new filter off course.

Craig.

[johnan]

I would also agree that a pre heater is a good thing, but the initial cost is high and then there is electric power to pay for.

I use one in my Midget but it is mainly to reduce engine wear during the warm-up period when engines are at their most vulnerable.

John

[Highridge]

I thought you were trying to generate a discussion not pounce on folks and critizise them.

If you read what I put, I listed the items I would consider when the warranty is up, some of my suggestions are not relevant to you but are to me, such as the pre-heater as I only do 2-4 miles at a time.

Some pre-heaters use the fuel onboard, not external power sources.

I suspect some of my suggestions will aid MGP, some are recognised my professional motor sports as good tech, such as waterless coolant which has been used for many years in motor sport and like other commentors to this thread it amazes me why the motor indusrty continues to use water, guess its that built in obsolescance thing.

Personally I doubt very much you get the consumption you claim, the book MPG issued my the manuafcturer is optimal based on wind tunnels, sensors and reading from the car running in Mexico at altitude on a test circuit.

You could of course fit LPG and cut your fuel bill but technically the MGP will drop as LPG has a lower combustion efficency, I ran an LPG Range Rover for a year and would never do it again.

[craggle]

Why wouldn't you go LPG again Karl?

I had a 4.2 Range Rover LSE and a later a 4.6 HSE running on LPG and both were perfect for nearly 8 years. Only sold them as they were still a bit expensive to run, even on LPG! :)

Friend of mine had a pre-heater on his V8 Land Rover. It was plugged into the mains on a timer to warm the engine 30 minutes or so before he left for work. Worked great until he drove off one morning forgetting to unplug it!

Craig.

[Highridge]

It was so hit and miss, I used to track the amount that went in and the milage I got.

I only got 12 to the gallon with LPG and in the cold it was even worse.

I was an LSE and a very old single point system.

I also only have 1 LPG station in the area and once they had no LPG for a few days and it put me off.

Maybe if I had to do long distance driving every day I would do it.

It also bothered me that it was not widely adopted and that hardly any new cars came with LPG.