Facing with the raising petrol price, i think its good time to discuss about how to increase the fuel efficiency of our car. I'm not talking about driving behaviour (ie light foot driving style), because that is commonly known already. What would like to discuss are other methods.

1) Engine Oil.


2) Tyre Pressure.


3) Low Rolling Resistance Tyre. (LRR)


4) Use of friction reducing Engine Oil Additives


5) Myth Fuel Saving Devices.


6) Updated: Iridium Spark Plug


7) Updated: High Flow Air Filter


My setup currently:
1) Shell Helix HX-7E 5w-30 SS (next candidate: LM MOS 10w30 SS)
2) 36-37 psi (my car's recommended pressure is 33-35 psi. pump over a bit because tyre is 'hot' when arrive at petrol station)
3) Bridgestone Ecopia EP150 165/65R14 (i heard that Mirage comes with EP150 as OE tyre. I bet it is one of the factor to achieve its claimed 21km/l )
4) Bluechem Oil System Care
5) duh. none.

The problem is I've serviced the car with HX-7E, changed to EP150, and used the EO additive in a relatively short period. So if the FC has improved, i dun really know which is the contributing factor.. note that all the calculations above are assumptions only... please take it with a pinch of salt. if got mistake.. please point it out and forgive me ya.

so guys.. any comment, disagreement, or better suggestion?? or do you think those i invested is more costlier than the fuel saved? opinion opinions

This post has been edited by efaceninja: Dec 4 2013, 03:30 PM

engine oil should be 0w20..

Not many cars can use 0W20, expecially older cars. But I know Honda Malaysia have cleared their cars to use 0W20 except Civic Type R. Dunno about Toyota & Nissan. VW recommends 5W40 in their cars, as do BMW & MB. Ford if I'm not mistaken recommend 5W30.

Anyway, some tips to save fuel: http://www.wikihow.com/Hypermile

True. wanted to save fuel but at the same time have to take note don't go too extreme until damage engine. If the car is recommended 0w20, then can use lo.

Hypermiling need behaviour changes. and human behaviour is.. kinda difficult to change

sell the car la...ride bicycle...saving more...aiyo!

not all cars can take thin oil...

Don't need to be so complicated.

1) Avoid roads with traffic jams
2) Be gentle with your footwork
3) Use light and small cc cars

1) not always able to do this
2) already very gentle with footwork, but wanted to push the FC FURTHER
3) already use light and small cc cars, but wanted to push the FC EVEN FURTHER

Just back to basics, train your foot especially if you're driving an automatic transmission car. How you step on the accelerator can also influence the shifting point and all. Maintain low RPM as much as possible, preferably below 3,000.

Bear in mind you may be spending more money by considering the methods in your 1st posting above to gain perhaps minor or negligible savings in fuel consumption. If you want to go to the extreme : -

4) Turn off engine when at traffic lights for long periods
5) Don't use air-con
6) Side mirrors folded to minimise drag (you won't be able to use side mirrors anymore) - negligible effect to FC anyway

In the end, it is a better idea that you ride a bicycle to work, provided your house is near to your workplace.

I agree, faster to top gear, lower fuel consumption.. right foot and left foot is also important, accelerate smoothly, and cruise to stop.. less brake usage, less energy converted to heat.. engine brake when possible.. been getting 17-18km/l on my '00 kenari, cruising @2.8k to 3k rpm @ 80-100kmh.. ard 5.5 - 5.6 l/100km.. official is 4.9l/100km... mirage sure can do better ...

Get a night job, no traffic jam, temperature lower use lower or no need air cond ...lol...

First of all don't over inflates ur tyre, u may lost grip & brake power not forgetting high chance of aquaplaning, the most important thing to save is ur own life.

Secondly stop believing those crap additives, it waste of money & in fact increase the oil viscosity thus more fuel consumption, if not causing sludge buildup in ur engine, use additives only when ur engine getting old & need a thicker oil to prevent engine oil lost.

Lastly do store unessary item in ur boot, alway inflate ur tyre in accordance with mfg recommendations at lease every 10 days, if u need to wait long in a traffic switch to neural gear pull the handbrake instead of stepping on brakes.

Get a night job, no traffic jam, temperature lower use lower or no need air cond ...lol...

First of all don't over inflates ur tyre, u may lost grip & brake power not forgetting high chance of aquaplaning, the most important thing to save is ur own life.

Secondly stop believing those crap additives, it waste of money & in fact increase the oil viscosity thus more fuel consumption, if not causing sludge buildup in ur engine, use additives only when ur engine getting old & need a thicker oil to prevent engine oil lost.

Lastly do store unessary item in ur boot, alway inflate ur tyre in accordance with mfg recommendations at lease every 10 days, if u need to wait long in a traffic switch to neural gear pull the handbrake instead of stepping on brakes.

Don't drag race with other road user ..lol...

I'm aware that i shouldn't invest more money to push the FC that wouldn't save my initial invest cost. a) i changed the engine oil to 5w-30 only when the service is due, not when my previous 10w-40 is still fresh. b) i changed tyre to Ecopia EP150 because my previous tyre set already reach the tread wear indicator already. in fact has been running on wear indicator for a few months already. So in this way, i don't consider myself "spending more money".

4) this is one of thing i wanna ask, is it okay for normal car (aka car that don't comes with stop/start system) to do manual stop/start too?? i know this is fuel saving but some ppl said the engine starter will very fast rosak.. and maybe the battery strain is higher also because i'll be using air-con when the engine is stop. Anyway i did this once because stuck in super traffic jam, didn't move for like 10 mins ++, off engine, off air-con, very hot
5) malaysia is too hot, i cannot give up air-con. but i do tune the temp knot to what i feel ok
6) i don't have electric self-closing side mirror.. and not to mention its super dangerous to do so. not feasible


Do you consider me over inflating already?? i dunno, because my theory is that, the car's recommended tyre pressure printed at the side of the door is "cold" pressure *Source-Wikihow*. But for me, i drove a long way and when i reach a petrol station, my tyre is "hot", and so i should pump "hot pressure" aka pump a bit more than the cold pressure stated.

fuel additives, i dunno, but my eagerness to try out this particular brand is just too strong

for my car, when going downhill, if i using D gear.. it will automatic to down shift gear and my rpm will suddenly go to 2 to 3k.. should i engage it to N gear??

for me, my weapon of choice would be a diesel car/pickup/suv

Can no problem to engage N during downhill, those longkai will be happily awaiting u in front, so that they can toll ur car & sent to their workshop to slaughter u (figurative speaking offcoz. .lol.)

Don't do that u may lost control of ur car, not mentioning causing damage to ur gearbox, guess I don't need to remind u gearbox been the most expensive part in ur car, by doing so have u ever think that ur car is still in motion when u re engage into D gear later ? since auto car had no clutch for u to temporary release the gear from clutch, u gearbox may be damaged by such move.

If u worry on the cold/hot pressure, just release some air from ur tyre before pump, anyway from what I "heard" not confirmed modern electronics air pump will calibrate ur tyre pressure automatically.

Can consider installing 4 Tayar Sotong "or Space saving spare tyre, cannot go above 80 km then sure save fuel ...lol..

Can try but "hopefully" no harm done.. ;-)

You're probably right. Normally what I'd do is to release air from the tyres by pressing on the valve by about 10 ~ 15 PSI or until I feel the air coming out is not hot, then I'll pump slightly higher than the recommended, which is also 34 ~ 35 PSI for the front wheels for mine.

No. No throttle input while car is moving higher than a certain speed should mean that no fuel is being supplied to the engine since the movement of the wheels should keep the engine spinning if the gear is engaged.

so u guys means i should let it on D when going downhill rite? forgot to mention that my gbox is cvt gbox.. but when i going downhill by using D, it make my car more slow to go down n the rpm straightly go up.. i think that is wasting fuel... haizz

u want more better FC? maybe you should perform weight reduction. throw out unwanted seat,change bodypanels to carbon fibre. change to smaller alloy wheels,smaller tyres needs less torque to roll.

watch out your right foot - very important too

clean carburetors / throttle body

Toyota Prius PlugIn not bad. I like.

Wanna get more FC to be train urself stay at home for most of times... That is settle

Ha ha yesterday night, with my family wanna go for mamak shop for eatting roti canai only.
I am chose the far from my Tmn to 15km around there.
End up my wife sound me eat at our Taman is ok already, just took me less than 8km from my house to the shop, we also happy to enjoy the roti canai..

Save save save.. 20 cent & 20 cent increase like no tomorrow already.

if cvt gearbox, i think its normal that the engine rpm will go up quite a lot when you completely let go throttle, same effect as if normal AT switch to 3rd or 2nd gear manually. Not sure if in cvt case, it would be fuel wasting or no. If normal AT, most ppl advice don't switch to N at down hill or slowing down before red light. keep gear in D and let the wheel drive the engine, the ECU will sense engine is at very low load and reduce fuel injection to very low or almost null. Then at complete stop at redlight, shift to N.
agreed on weight reduction but what you suggest is a little bit too extreme for me.. haha might ended up investing more than fuel save. Read somewhere before that, remove the spare tyre from the car. replace it instead with those emergency inflation kit/bottle, and emergency tyre repair kit.
this method confirm fuel save the most, but its save by not using. I'm more to save by increased efficiency.

Over-inflated tyre is not something recommended.
An over inflated tyre can cause the tyre to crack, wear faster (at center) as well, which means more money wasted, as well as risk of blow out which can be very dangerous especially travelling at high speed at highway time.

Also over inflated tyre can have less grip which is risky, that can cause accident. An accident can cause more money, as well as risk of injury and life.
So don't be penny wise and pound foolish.
Always use the optimum pressure recommended.

Tyre pressure generally stay quite constantly, if using everyday, it is unlikely to lose pressure from 31 psi to 21 psi, just a month or 2 using.

Safety is always the top priority.

The better way to save money is planning destination route properly, park you car whenever got parking space, don't go few round just to look for "nearer" car park.
Don't go to far for shopping just because there 2kg Milo pack is selling Rm2.00 cheaper. (I see many did this)
Light footer
Drive smoothly, instead accelerate fast, and break hard approaching junction/traffic light.

Many more effective way to save money, instead try to over-inflated tyre which can be dangerous.

Slight over inflation is ok. Some cars have two inflation schedule. It is safe to use the higher one.

Remember it is COLD pressure, that is pressure in the morning when your car hasn't move.

Blowout happen because of tyre failure. Tyre failure happens because of heat and heat is caused by *under* inflation. Under inflation causes the tyre to lose some rigidity leading to more deflection causing the tyre to heat up.

The cold pressure vs hot pressure is not significant, it is not the like PSI will rise 5-10 during "hot" time.

Get the fuel efficient car/engine, light footer, eliminate unnecessary travel, is better than those trivia issue, or get a light weight small car is miles better whatever effort try to do.

Yes, good to choose those more "saving" method, but not until try to over-inflated the tyre, purpose stop the engine during traffic light etc. <--- use hybrid car if intend to save fuel by stopping at traffic light, as hybrid save those fuel into battery.

Stop/start more often make battery shorter, which a battery can cost Rm150~200, so whatever saving from fuel (by stop/start more often) may go to battery. Not to mention potential more wear and tear on engine part.

Both under-inflated and over-inflated also not something good and recommended.
Both increase the risk.

Less grip due to over-inflated tyre can be as dangerous as well.
Yes, slight over still ok, not the like significant over.

Cold vs hot can be insignificant for here, as temperature here difference is not the like from zero to 40C.

just pumped rm50 foor the new rm2.10 petrol. trying out bhp as suggested by some forummers for saga blm. the petrol feels so 'little', rm50 only get 23litres now.....woo woo, drive carefully and see how.

Staying at home will cause economy stagnation, then recession, pay cut, job lost...lol..

Get a bicycle or walk to near by destination, save fuel, exercise & boost local economy...can burn those extra calories from roti canai & teh tarik ...lol...

Funny. I usually hear the recommendation to overinflate the tyres. Not to the extreme of course, but 20 kPa more than recommended is good, more than that still acceptable. It reduces tyre wear cause the tyre isn't dented so much anymore (it keeps deforming while driving, by reducing that it won't be as hot anymore, it won't be worn out so fast), though you may loose a bit of grip by reducing the contact surface if you go too far. Also the manufacturer recommends increasing the pressure anyway depending on usage... i.e. if you mostly drive on highways it should be higher, if you have heavy loads in the car, ... The main advantage of a not so high pressure is comfort.

Being UNDER the recommended pressure is bad however. The tyre wears out faster, handling will suffer, let alone the increase in fuel consumption.

I usually drive with 240-250 kPa. No problems.

Btw., IIRC there was a 20 kPa or so increase from cold to hot tyre... so yes, it is quite a bit. And hot means like driving 3 minutes.

Cold vs hot here i don't mean the ambient temperature of malaysia. i meant the temperature raised due to air friction within the tyre itself. from what i observe is quite significant. ie last time before i go out in the morning, i checked tyre pressure using my pressure gauge (cheapo type la ) is 31psi. then after come home in evening/night or so, check again and the pressure is 33-34 psi.

kind of agree with you here. i think the strain to battery and/or starter is too great. not to mention no aircon during engine off!

don't have bhp at my area currently using petronas most of the time.. read on some forums that mentioned shell's 95 is not that good. but from my experience, i can't really tell any difference

lols, true .

agree with you here. keypoint is SLIGHT overinflate

That's what I meant too, and the difference is similar to what i heard. Maybe next time you can test before you drive, and then after a few minutes test again. I'd love to see how much difference it really makes in Malaysia.

Hm. I do turn off the engine when parking... i.e. I full blast the aircon until the temp is ok (with the aircon set to cycle the air inside the car... not sure what the name for that feature is), then off the engine, and when it gets too hot I start the engine again. So maybe every 10 minutes keep the engine running for a minute or two.
I run 36 psi (but with warm tyres), I guess that is acceptable. I wouldn't go any further than that though.

retune your ECU. Include lean cruise. A bit extreme but it does help.

In Malaysia, is there such place to install "belly pan" for the undercarriage ? First it does improve aerodynamics which gives better fuel consumption. Second, it protects the undercarriage from being damaged by rocks.

Yeah, but where does your engine heat will flow?

to be honest, i think the best is still to train your driving habits la. unless your car is seriously that badly engineered or so old that its wasting large amount of fuel, doing any of the things like changing viscosity and over inflating tyres are not going to do much.

your right foot is the biggest contributor to high FC, tame it is all you really need to do. anything else will save you probably like few percent here and there and is just not worth the effort/danger/damage you likely cause to your car

on a related note, i personally think hypermiling is stupid, dangerous, and downright irritating.

hello.
just changed 2 new front tyre, Sime only la at rm160 x 2.
the shop pumped in over 35kpi and my blm jumps on the road, so weird but haha very funny ride. will reduce the pressure to 31 as recommended.

All the sifu here already teach on how safe fuel, (Constant speed, Off aircond, Reduce drag, Inflate the tire, Reduce weight and last proper maintenance of your car - no skipping the service schedule).

Stay @ home and do more online shopping to keep the economy going..

well depending on tires, it CAN inflate further 5-10psi during hot.

my tires does just that especially after spirited driving which can rise from 32 to 40psi or so.
then again they aren't meant for eco.

just thought i'd clarify this a bit

Actually, one can calculate how much the pressure will be under hot, using thermodynamic equation
PV=nRT.
As volume of tyre volume remain constant so

P (cold) =nR T(cold)
with
P (hot) = nR T(hot)

so the air inside must be very very hot, if it manage to rise extra 8psi on its own.

Can someone doing the math to see how much temperature rise to have extra 8psi.

i released the air inside before and it was almost scalding like (fingers gotten a bit red lol)

i would assume that it'd be damn hot?

If it rises 8psi on its own, it should be burning already, as temperature needs to rise more than a few ten of degree C to have so much pressure rise.
Again, anyone help on the thermodynamic calculation, to show exact how much temperature has risen that can result in 8psi rise.

Ambient temperature assume 30c.
which is 303 K (273+30)

Pressure 30 psi at 303
Pressure 40 psi at ?

32/303 = 40/?

? = 378K

378 - 273 = 105C.

Please correct me if I am wrong, thermodynamics rusty already.

it didn't felt like 105c though else i'd have burns

iinm i read somewhere about 10F increase would increase about 1 psi, so 8 would be 80F and thats about 26C, +30 would be about 56 which seems about right for the temperature i felt when i release air pressure.

May be I get the unit and formula no right, as said rusty already.

Unit problem.
Tyre pressure = 32 psi *relative* to atmosphere. Absolute pressure is tire pressure + atomospheric pressure
Assume 1 atm pressure = 14.7psi

Therefore
P1 = 32+14.7 psi = 46.7 psi
P2 = 40+14.7 psi = 54.7 psi
T1= 30 + 273.25 = 303.25 K

Since nR and V are constant

P1/T1 = P2/T2
T2 = T1(P2/P1)
T2 = 303.25 * (54.7/46.7)
T2 = 355.20 K = 81.95 *C

Thus temperature increase
T2 - T1 = 81.95 - 30.00 = 51.95 *C increase

If pressure only increase to 38 psi, temp would be 68.96*C. This is for *ideal* gas. Air is not ideal gas, it consists of many types of gas and water vapour (moisture). Air temperature does not increase linearly with pressure. Pure nitrogen however is close to ideal gas behaviour.

My thermodynamics is rusty also. Forgotten how to take in account partial pressure of the gasses.

This post has been edited by sanadi: Sep 17 2013, 05:43 PM

Fuel efficiency had turn into complex physics calculations ...lol...

Maybe should get Soft, Medium & Hard compound tyre, don't forget semi & full wet tyres too change according to road temperature & weather ...rofl...

Cabut....

This post has been edited by jolokia: Sep 17 2013, 06:59 PM

You'd need a pit crew travelling along with you.

Over-inflating by just a bit is quite safe...provided that you know that you are not cornering very hard/fast, and will not be operating the vehicle beyond the recommend loading. You don't need to over-think the "extra load" bit. I'd look at my passengers and cargo to have an estimate. I've never had to worry about that even when there a 6 occupants in my car (Myvi BTW). However, most of the time my passengers are small petite women, so...

But none could replace driving habit. The trouble is, lots of people confuse between driving gently and slowly. Driving slowly will just be annoying to everyone else (unless you're doing it for safety reasons like carrying a s***load of durians at the back seat, then carry on).

There's no need to over-think it if you want to save fuel. Drive at the speed limit, and be patient when getting to that speed limit, just those for starters. There are various driving tips all over the net. I've seen a person from a forum getting 11km/l using a '76 El Camino with a 5L V8 auto, no mods just driving technique. If that person can do that with that car, what excuse do we have driving cars much smaller than that?

ok i'll be honest here, i fail my math during school

some cars though are just not meant for driving "efficiently"

take for example my iswara... 3 speeder auto.
1st shift is at 20km/h, 3rd and final shift is at 40km/h. so if i wanna stay at minimal throttle input/sub 2-3k rpm, id be sitting between 40-60km/h.

surely, it improved my FC from 7-8km h to EASILY 8-9 km/h or so despite i STILL pull off red lines when the traffic permits... but damn it is hard to break a hard revving habit and go 40km/h most of the time.

for reference: http://www.fuelly.com/driver/quazacolt/saga

Sorry, got carried away with the calculations.

I agree with you. The key to eco driving is smoothness. Do not drive too slow or accelerate too slowly. Not only is it dangerous, but the fuel saving will be wiped out when you got rear ended and have to repair the bumper. Maybe only RM300 but can the fuel you saved cover that? Your are saving fuel, but not saving *money*. At the end on the day it is *money* that we want to save. (Maybe environmentalists don't think so?)

My advise for saving fuel and money that give to my friends:
* avoid jams if at all possible
* avoid idling. Need to wait for someone? Shut the engine and wait outside the car. (If safe & possible)
* accelerate normally, at a relaxing pace. Not too slow and not too fast.
* drive the speed limit
* lighten your car by taking out the things you don't need. Your don't need to always put your grass cutter in the boot. Take out. But don't take out your spare tyre or your emergency kit. (If you have to call a tow truck when you have a punctured tyre, expect 3 digit charges, unless your insurance covers it)

fuel saving topic is nothing new.

9 basic steps if you really into it:
http://www.wikihow.com/Save-Petrol

When waiting for someone you can (when save) open the windows too. Lots of wind sometimes, very cooling. Even a bit (so that others can't really attack you) helps. Maybe just open the opposite site so they can't take a knife to your neck.

Hm. One of the reasons why I overinflate a bit is cause I'm scared the tyre gets torn off the rim when cornering Wrong thinking?

An optimum tyre pressure shouldn't have this happen.
Normal car won't be cornering 60~90 degree like F1 at >100km/h.
You turn turtle instead.

Haha, I'm driving on 185/65 R14 though... if it were 195/55 or so I'd agree. I've seen my car on the Nordschleife with a camera mounted next to the front tyres, and it was a scary sight. In terms of bodyroll I don't think that's so easy to achieve (not enough grip from the XM2...), though if I do slalom I would eventually play turtle...

just keep ur RPM below 2 if possible or max 2.5, then you're golden

I know how fun it is and I sometimes find myself a very large empty parking lot to ease off my addiction (I like the feel of throttling up after a very hard corner).
If you really want to save fuel but not change your car I guess you either live with it or dump the habit.

It's got a long ratio; the 3rd gear on iswara is about the same as the 4th of a Myvi manual box. Not a highway cruiser for sure, but I think it won't do too bad at the lights. I'd say tune the carb just to be a bit lean but that would mean you'd REALLY have to say bye-bye to the high-rev habit. Change carb maybe (if you haven't done so already)?

You'd have to "crawl" that thing off the lights but you'd be annoying everyone behind you. I know I would be if I were behind you, eventhough I am a hyper-miler.

it's at 13.5 AFR, pretty lean btw.
my engine is typically running lean so the temperature is a bit on the high side.

well, now i can indulge in some other fun shenanigans which is floor/downshift if someone decided that my crawling is too annoying

hahahha just reading back today. perfect gas equation also come out. so in the end, still over inflate a little bit, when tyre is hot.

very very agree. and btw, shouldn't you put durians at the trunk? Imagine if you really unlucky get into car collision, then all the thorns flying in your car...

So far most of the thread here talk about drive gently etc etc to save fuel.

That is what WE can do to save fuel.
So how about.. what our CAR can do to increase FC???
For example to avoid traffic jam, sometimes really hard to do. Only thing to rely is probably waze? Then, if really stuck in jam already, isn't the last thing that can probably can save/reduce fuel is a duper good engine oil?
So far i've done (and monitoring) the 4 thing mentioned in the first post.

erm. 13.5 is rich.

changing to a much fuel efficient car is better than installing those fuel saving device. IMO

Take rm5k, buy a used kancil. U save not only fuel but also cheaper tyre, cheaper service, cheaper parts, cheaper road tax, cheaper insurance and look cheaper. But hey u save tons of hard earn cash yo.

1. Motorcycle
2. Find a new home nearer to your workplace, perhaps walking distance if possible.

But if you have an accident you are more likely to end up disabled (unable to work) or dead. Sometimes there is a thing like being too cheap (of course, if you have to, then you have to, but if you have the choice better get something a bit safer).

Another option is the F30 BMW 320d. Super low fuel consumption, better than Kancil. Or BMW i3. No fuel consumption

This post has been edited by kadajawi: Sep 19 2013, 01:38 PM

Wah.....BMW so expensive, the expensive-ness can cover donno how many decades of full tank fuel liao.


Sometimes really fated liao, some drive entire life motorbike oso no die, some drive super safety car also still die. If drive kancil, drive slow slow lor.

Then buy a Saga SV or Executive over a Vios, even if the Vios saves a bit.

You can move your luck into your favour though. Drive a safe car, and drive it sensibly. If you drive like an idiot you can't be saved. Of course there is no 100% guarantee you will not die in an accident, but if you look at worldwide statistics you will see that Europeans are much less likely to die on the road than Malaysians. There are various reasons for that, like drivers behaviour/education and the cars driven (also what they are focused on... Only if a car has absolutely everything will it also get safety features. Overseas it is the other way round... Even an empty car with steel rims will have ESP and 6 airbags).

A few days ago I saw a Kancil full of durians at the back seat.

I've read somewhere that the rear ventshades can be taken off if you travel at the highway often. You can leave the front ones on as the shape of them and the way they face the wind doesn't make them as detrimental.

There is some modification that could be done to the front, such as making a vertical slot at the rear-most part of the front ventshades, closest to the B-pillar. You'd have created a slot for trapped air to get out of while still protecting the interior from getting wet.

No scientific testing has been done about that but they guy who did it (IIRC) did notice a fair degree of wind noise reduction.

I'd test it myself but the tape they are so well put on after 8 years they still stick like new, I'm afraid that I'llcrack them and have to buy a new one.

Other things you could do to your car:

1. Tint your windows (legally).
2. Fix any dents on the body.
3. Change mudflaps. Those square flat ones aren't good in the wind, and there are alternatives that provide the same protection. Ones on newer cars, those small stiff plastic things are good and they curve into the shape of the under-body for better aerodynamics.
4. Better air filter. Though this can be a bit expensive and if not chosen properly can provide no additional benefit. What you may get is better performance with the same fuel economy (not actually increasing it).

Things like CAI may only be useful if your engine is running super hot, and a bit lean I think. The cold air just makes it a tiny bit more difficult for fuel to vaporize. Unless you want to go full on racing and heat the fuel pre injection. Dangerous by the way, and expensive. Don't do it.

This post has been edited by VagueConcerns: Sep 24 2013, 11:34 AM

This one looks very real, and my BLM saliva also come out.
Really can or not? Will sifus give some ideas please? these shd benefit many of us here.
Thanks.


http://www.youtube.com/watch?v=ra03WLtfTug

There are too many variables in play there. He could be having head/tail wind on either trip, and the test was done in one day, while these real world FC test should be done in weeks preferably.

There are also too many ways to cheat. He could've pushed the car hard for the first run, and then drove lightly for the second. And the way to measure the fuel was crap. The proper way is to have a small amount of fuel from a separate container which contains a certain number of litres of fuel (10 maybe), not relying on the reading from the fuel pump which may have slight errors. Then after each run pour the fuel out and measure what's left. And this should be done preferably in a test environment like a circuit, or even better a rolling road.

try drive consistent speed for a very long time.. but in city area sure hard to do..

Perodua Kenari can use 5w30 oil???

0w20

can..