Was at a tyre centre and I asked one of the staff what he felt was the best tyre pressure for my Toyota Avalon.
He reckoned 38 pounds which really surprised me.
Think the manual recommends 32 but I have been using 34 for the last 5 years.
Anyway,I filled the 63.5 litre tank to full to see if it would improve my fuel consumption.
Usually get 650 Kms out of a full tank - that's driving in neutral at every opportunity.
Most I've got was 670 Kms.
To my surprise I achieved dead on 700 Kms yesterday.
There is a rather large negative though - my car is no longer smooth to drive - you can feel every bump 
Going to drop it to 36 for a balance of smoothness and economy.
I was in a tyre centre recently and the guy suggested to put Helium in the tyres.
reakons it will improve fuel efficiency and tyre life through running cooler, $10 per tyre
Was in a rush so didn't do it.
Has anyone else tried this in an SUV?
Select to expand quoteGWatto said...
I was in a tyre centre recently and the guy suggested to put Helium in the tyres.
reakons it will improve fuel efficiency and tyre life through running cooler, $10 per tyre
Was in a rush so didn't do it.
Has anyone else tried this in an SUV?
Tried the helium in my tyres once.don't like the noice it makes when l get a flat.
Nitrogen is often used in racing tires on the track as it isn't susceptible to temperature change. many other competitors would use it when i was racing bikes at barbagallo. I didn't because i couldn't afford it at the time 
.
Select to expand quoteGWatto said..
I was in a tyre centre recently and the guy suggested to put Helium in the tyres.
reakons it will improve fuel efficiency and tyre life through running cooler, $10 per tyre
Was in a rush so didn't do it.
Has anyone else tried this in an SUV?
The amount of helium here on planet earth is very limited.
Because it's so light, it accumulates in the upper atmosphere where it's blown away into space by solar winds etc, never to be seen here on earth again.
It has some critical uses in devices where super cold temperatures are required to be maintained.
At this point in time, helium is the cheapest and most effective gas available which can operate at the low temperatures required to maintain superconductivity in super strong magnets.
It's probably not the best use of such a critical and diminishing resource to use it to pump up car tires.
Yes, I know they waste it in party balloons and on other useless causes but probably best not to establish another one, unless you are into some serious racing or similar.
Pump your tires up with air, and if you want them to run a bit cooler, then pump them up a bit harder, or you could even try driving a bit slower.
Select to expand quotepweedas said..GWatto said..
I was in a tyre centre recently and the guy suggested to put Helium in the tyres.
reakons it will improve fuel efficiency and tyre life through running cooler, $10 per tyre
Was in a rush so didn't do it.
Has anyone else tried this in an SUV?
The amount of helium here on planet earth is very limited.
Because it's so light, it accumulates in the upper atmosphere where it's blown away into space by solar winds etc, never to be seen here on earth again.
It has some critical uses in devices where super cold temperatures are required to be maintained.
At this point in time, helium is the cheapest and most effective gas available which can operate at the low temperatures required to maintain superconductivity in super strong magnets.
It's probably not the best use of such a critical and diminishing resource to use it to pump up car tires.
Yes, I know they waste it in party balloons and on other useless causes but probably best not to establish another one, unless you are into some serious racing or similar.
Pump your tires up with air, and if you want them to run a bit cooler, then pump them up a bit harder, or you could even try driving a bit slower.
i think he was joking. helium is so small a molecule its hard to contain. the tire places do use nitrogen though. it doesnt suffer from temp so much
Pete, try pumping them up to 45 or even 50 psi, your fuel economy will improve even further, and as an added bonus you will only use the middle third of your tread on each tyre.
Select to expand quotepetermac33 said..
Usually get 650 Kms out of a full tank - that's driving in neutral at every opportunity.
If you park your car in front of the funny farm and check yourself in you will spend even less on fuel.
I seriously don't believe anyone drives in neutral unless they are not a full quid!
Select to expand quotepweedas said..GWatto said..
I was in a tyre centre recently and the guy suggested to put Helium in the tyres.
reakons it will improve fuel efficiency and tyre life through running cooler, $10 per tyre
Was in a rush so didn't do it.
Has anyone else tried this in an SUV?
The amount of helium here on planet earth is very limited.
Because it's so light, it accumulates in the upper atmosphere where it's blown away into space by solar winds etc, never to be seen here on earth again.
It has some critical uses in devices where super cold temperatures are required to be maintained.
At this point in time, helium is the cheapest and most effective gas available which can operate at the low temperatures required to maintain superconductivity in super strong magnets.
It's probably not the best use of such a critical and diminishing resource to use it to pump up car tires.
Yes, I know they waste it in party balloons and on other useless causes but probably best not to establish another one, unless you are into some serious racing or similar.
Pump your tires up with air, and if you want them to run a bit cooler, then pump them up a bit harder, or you could even try driving a bit slower.
Sorry if this is a stupid question, and yes - I could Google it - but if helium is so light and keeps floating off, where does it come from?
Yes you got better fuel economy, but like Chris said, over inflated will mean centre wear. Everything has an optimum range.
For normal (not really low profile) tyres use the 4psi rule:
Drive half an hour in 110 zone and tyre pressures should go up by 4psi. Anything more, they were too low to start with and the tryre deformation and friction increased heat = pressure up.
Any less than 4psi increase they were too high to start with.
Then, to get pressures right relevant to how you drive, and assuming alignment is correct: also look at wear at the time of getting new tyres. If you always run a certain pressure but outside shoulders are worn off, you need more pressure. Move evident on front tyres of young chicks cars that get thrown around corners with 20psi and strangely enough they understeer badly and wear outside shoulders.
If you have centre wear, you are over inflated. Or need to go around corners faster 
Anyway Avalon being fwd, go 38 front 32 rear. Enjoy the handling improvement (within the limits of a sloppy thing designed to understeer).
Far as I know helium comes from the oil industry. Trapped underground and is brought up with the oil. Finite resource, bit like the planet as a whole really.
Select to expand quotepetermac33 said..
.........driving in neutral at every opportunity.
How do you drive in neutral?
Over inflation can also cause the tread to "sawtooth" and the tyre will wear quicker. Also, what Mark_australia says.
Select to expand quotelightwood said..
You need 22psi and a polariser.
And a hiclone!
Select to expand quoteDavMen said..petermac33 said..
.........driving in neutral at every opportunity.
How do you drive in neutral?
Angel gear going down hill, hope your brakes hold out and you don't get up too much speed
Select to expand quoteDavMen said..petermac33 said..
.........driving in neutral at every opportunity.
How do you drive in neutral?
You wait for the flat earth to tilt in the direction your'e going and then to get home you once again wait for a favourable tilt and off you go.
Select to expand quoteVince68 said..
Nitrogen is often used in racing tires on the track as it isn't susceptible to temperature change. many other competitors would use it when i was racing bikes at barbagallo. I didn't because i couldn't afford it at the time .
Biggest scam on the planet. The air is already 80% nitrogen, and nitrogen and oxygen are pretty close to each other on the periodic table. Glad to hear your didn't waste your money.
Always lived by the 4 psi rule. 
Some vehicles with live front axles struggle to achieve even wear across the whole tyre contact area.
Nitrogen is moisture free so doesn't cause icing inside aircraft tyres at altitude and balance problems during the landing.
Select to expand quoteAUS1111 said..
Sorry if this is a stupid question, and yes - I could Google it - but if helium is so light and keeps floating off, where does it come from?
Clown farts.
Select to expand quoteGWatto said..DavMen said..petermac33 said..
.........driving in neutral at every opportunity.
How do you drive in neutral?
Angel gear going down hill, hope your brakes hold out and you don't get up too much speed
Coasting in neutral actually uses more fuel than coasting in gear...when in neutral the engine consumes fuel at idle speed.
When in gear the wheels turn the engine over and it consumes no fuel at all (especially modern fuel injection)...this is where a lot of hybrids gain their charging.
Also it is not very safe...if you need to accelerate urgently you have to get into gear first, and then it may not be the right one.
Select to expand quoteAUS1111 said..
pweedas said..
GWatto said..
I was in a tyre centre recently and the guy suggested to put Helium in the tyres.
reakons it will improve fuel efficiency and tyre life through running cooler, $10 per tyre
Was in a rush so didn't do it.
Has anyone else tried this in an SUV?
The amount of helium here on planet earth is very limited.
Because it's so light, it accumulates in the upper atmosphere where it's blown away into space by solar winds etc, never to be seen here on earth again.
It has some critical uses in devices where super cold temperatures are required to be maintained.
At this point in time, helium is the cheapest and most effective gas available which can operate at the low temperatures required to maintain superconductivity in super strong magnets.
It's probably not the best use of such a critical and diminishing resource to use it to pump up car tires.
Yes, I know they waste it in party balloons and on other useless causes but probably best not to establish another one, unless you are into some serious racing or similar.
Pump your tires up with air, and if you want them to run a bit cooler, then pump them up a bit harder, or you could even try driving a bit slower.
Sorry if this is a stupid question, and yes - I could Google it - but if helium is so light and keeps floating off, where does it come from?
Most of it is produced as a by-product of the oil and gas industry.
It's one of the many dissolved 'impurities' which is removed during processing.
Although it's only a small percentage and would normally be vented off into the the atmosphere, because there are so few sources of it and it's in such limited supply it is saved, and has been for many years. However, we are now using it faster than we are making it, which is why I suggest we should not be in a rush to use the rest pumping up tires, or party balloons for that matter.
{edit} oh, I see RumChaser has already said it. And your cat is drinking from the toilet bowl. 
I hope you remembered to flush it,.. before the cat started drinking. 
30 KM extra over 670 KM or 4.5% is hardly a big deal. Tail wind? Driving in neutral is a very stupid thing to do. If your engine cuts out, you have no power steering. Worst still, the steering may lock up. Your driver's manual will have information on the appropriate pressure for your tyres. Playing around with tyre pressure above and beyond the recommended guide is asking for an accident.
By the way, curse the creator who put lumps and bumps on the flat earth. Wouldn't it be nice if we can just get up to speed and put it in neutral. But a set of good brakes still is a good insurance when you reached the edge, innit ?
Select to expand quoteJupiter said..
Your driver's manual will have information on the appropriate pressure for your tyres. Playing around with tyre pressure above and beyond the recommended guide is asking for an accident.
How so?
Select to expand quoteMark _australia said..
How so?
Too low pressure, tyres will heat up. Not only that, if too low, it will roll off the rims.
Too high, it will also cause stress on the tyre carcass, potentially a blown tyre.
Car manufacturers put a tyre pressure sticker on your car not just to add a bit of bling, I reckon.
Select to expand quoteCar manufacturers put a tyre pressure sticker on your car not just to add a bit of bling, I reckon.
and usually it is a pressure that is too low, so as to give you a softer more comfortable ride to promote their product.
Select to expand quoteJupiter said..Mark _australia said..
How so?
Too low pressure, tyres will heat up. Not only that, if too low, it will roll off the rims.
Too high, it will also cause stress on the tyre carcass, potentially a blown tyre.
Car manufacturers put a tyre pressure sticker on your car not just to add a bit of bling, I reckon.
I know that.
I was asking how playing with tyre pressures is "asking for an accident". Exagerration much?
If I run 34 instead of 32 am I playing with people's lives? No.
Tyres have quite a broad operating pressure range within which they can safely operate.
Tyre pressures relating to cars are set so as to compliment (or hide inadequacies in) the suspension, Formula 1 cars use the high profile tyres as large part of their suspension ride role.
Bumping up the pressures on your road car will often help with fuel economy and make the car handle better by not having the tyre flex on the rim as much when cornering.
Even better economy can be gained from Silica impregnated rubber compounds which give good grip but less rolling resistance.
