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TYRE PRESSURES!!!


peregrine

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Much has been said about correct tyre pressure,profile and size (tyres that is). Main topics relate to performance, followed by economy but very little, about what the Pneumatic Tyre was originally designed to provide, a comfortable ride with improved handling as a by-product. This thread has been placed with a hope to encourage comments and help in regard to improving comfort and the various aspects tyres play as part of this equation. Take my car for instance. A 1999 Vienta designed for comfort, silence and prestige, (while still being no slouch to performance), which is usually driven in a sedate fashion in keeping with my age. While my previous car a Ford Fairmont, a car of approx similar size and weight and yes rear wheel drive with exactly the same size tyres 205 65 15, used recommended tyre pressures for normal around town driving of 26psi front and 28psi rear. My Vienta has recommended tyre pressures of 32psi front and rear and as a result gives a harsher ride and I suggest places much more stress and strain on all steering and suspension bushes and parts than would a lower tyre pressure. Having checked with various organizations knowledgeable in these things Ive' dropped my tyre pressures to 28psi front and rear and find this much more acceptable. Yes I will put them up to 32psi on any extended trips in the country etc: I realize the lower tyre pressures might cause varying results, hopefully only marginally on steering and handling, not quite as good wet and a little better in dry conditions but I'm willing to trade those off and take it easy. All HELP AND INPUT APPRECIATED.

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The tyre wear will be quite a bit worst with such a low pressure. The thing with running on such a low pressure on a fwd car is your front left is going to chew the outside edge like no tomorrow. However over inflating the tyre will cause it to wear the middle of the tyre faster.

Edited by STYLSH
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The guy at my safe driving course was of the opinion that higher pressures (~250 kPa, probably around 35-36 psi) were better from a safety standpoint.

I heard that as well, cannot recall his exact reasoning but it was something to do with having more tyre surface in contact with the road. In the Sportivo I prefer to get about on 34 psi as my daily drive and don't mind the bit of ride comfort I sacrifice for the responsiveness and better handling I get in return. And before I go on a monthly meet when we're going to cruise I bump it up to 36 to compensate for the freeway drive down and the driving we do during the day so they don't end up losing too much.

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The guy at my safe driving course was of the opinion that higher pressures (~250 kPa, probably around 35-36 psi) were better from a safety standpoint.

I heard that as well, cannot recall his exact reasoning but it was something to do with having more tyre surface in contact with the road. In the Sportivo I prefer to get about on 34 psi as my daily drive and don't mind the bit of ride comfort I sacrifice for the responsiveness and better handling I get in return. And before I go on a monthly meet when we're going to cruise I bump it up to 36 to compensate for the freeway drive down and the driving we do during the day so they don't end up losing too much.

Softer tyre more road contact, bigger tyre surface contact. I'll keep an eye on tyre wear as I feel this could be a problem Due to front wheel drive.

Edited by peregrine
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The guy at my safe driving course was of the opinion that higher pressures (~250 kPa, probably around 35-36 psi) were better from a safety standpoint.

Doing the things you do there, with skid pans and excessive speeds I agree wholeheartedly.

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36psi front and rear.

We have 2 Camrys,... 2000 ser2 V6 and a 2006 ACV40R 4cyl and have found this to be the best for both cars after trying many combinations. They ride smooth btw. That is also the pressure recommended by every tyre fitter i've spoken to as well.

I would never run steel belted radials below 30psi... too much flexing resulting in overheating and belt seperation.

The 2000 V6 just received new tyres (Falkens) after delivering over 50,000k on a set of Hankooks and still had 10,000k plus safely remaining The new Falken tyres are brilliant.. smooth as silk and the handling is remarkedly improved.

The 2006 ACV40R has done 70,000 on the original Dunlops and still have a long way to go.

What brand of tyres are you running??

Some elcheapo tyres do give a rough ride among other surprises. :whistling:

A friend just had to replace his no name elcheapo tyres which would not have done 5000k... the wire belting was coming out through the side on 2 of them!! It was not through abuse either... he is over 70 and takes his time.

Cheers. :D

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36psi front and rear.

We have 2 Camrys,... 2000 ser2 V6 and a 2006 ACV40R 4cyl and have found this to be the best for both cars after trying many combinations. They ride smooth btw. That is also the pressure recommended by every tyre fitter i've spoken to as well.

I would never run steel belted radials below 30psi... too much flexing resulting in overheating and belt seperation.

The 2000 V6 just received new tyres (Falkens) after delivering over 50,000k on a set of Hankooks and still had 10,000k plus safely remaining The new Falken tyres are brilliant.. smooth as silk and the handling is remarkedly improved.

The 2006 ACV40R has done 70,000 on the original Dunlops and still have a long way to go.

What brand of tyres are you running??

Some elcheapo tyres do give a rough ride among other surprises. :whistling:

A friend just had to replace his no name elcheapo tyres which would not have done 5000k... the wire belting was coming out through the side on 2 of them!! It was not through abuse either... he is over 70 and takes his time.

Cheers. :D

Like your friend I'm in my 70S. I'm running, standard run of the mill tyres 205 65 15 Dunlop SP Sport 300E tyres chosen for acceptable handling and quiet running I also find them ideal for my type of driving. The 28psi pressure was suggested by the RACV who I find are very adept at providing accurate and meaningful information. However thanks for your response and your points have been taken. I suppose like anything with variables there are varying views each with their own merits and or mistakes. My reason for running softer tyres is to help place less strain on the rest of the undercarriage and a softer ride. By the way a 1994 Fairmont I once owned recommended 26PSI on the same size tyres and I B) had absolutely no problems Over thousands and thousands of kilometers with tyres of the same size (yes rear wheel drive)!

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I just re-read your first post and agree, tyre pressures are something that is subject to a lot of debate. What is right and wrong is a grey area and it is sometimes clouded in purposeful mistruths as well to fit an alternative agenda.

I'm no spring chicken myself being in my 60's but in saying that I have also had experiences with tyres in my motoring years. Things like the old tubed cross ply tyres, the polyglass tyres that were the slipperiest thing on earth, the first "rag" radials and then the introduction of todays steel belted tyres and their never ending problems of belt seperation.

Before I go further, in the end tyre pressures are an individuals choice regardless of safety, performance or wear. A bit like a cup of coffee, there are many variants and as to which is the right one is the individual's final choice.

Todays steel belted radial had a bumpy start to life, mostly bought on by people using pressures suited to earlier cross ply tyres plus bad tyre design in earlier years of production as well.

The problem of belt seperation was found to be caused by excessive heat caused by using the lower pressures of older days suited to cross ply tyres. They found that the rubber and steel heat and contract at a different rate causing seperation of the layers on cooling. They also found that using the lower pressures caused more flexing thus more heat and the eventual tread seperation.

The resulting tread seperation gave a bumpy ride as it produced a lump in the tyre. Most thought the wheel had thrown a wheel weight so had it re balanced and still had the bump.. bump.. bump. Those that took the situation to the extreme by not having the tyre examined ended up with a blowout. I have been travelling behind cars twice and seen it happen and luckily in both cases they were rear tyres and no accident resulted.

Lower pressures for a smooth ride and risk a blowout.. no thanks, is my personal choice.

Car manufacturers place a sticker on the door frame stating recommended pressures and these are more based on comfort rather than the safety or wear. After all if a prospective customer was test driving a new car and it gave a harsh ride they would look elsewhere.

Motoring bodies like the RACV, NRMA, etc will only recommend vehicle manufacturers pressures for liability reasons, they will never recommend otherwise even if they personally believe different.

Cars have changed dramatically over the years and that must be considered as well, what was good 20 or 30 years ago may not be suitable or even dangerous today. Apart from the much improved handling dynamics the majority of todays cars are front wheel drive which places so much ephasis on the front tyres while placing next to nothing on the rear. Power steering is also another factor as are our much improved roads.

This subject can be like the old question.. how long is a piece of string? So many factors to consider but when the dust settles it is your choice no matter what, not only how much pressure you use but how often you check them as well.

Having the internet today and it's endless amount of information would be the best source to persue more information on this subject because in a personal forum you will get 30 people and all will have different preferences.

BTW.. on our 2006 ACV40R Camry we still have the original factory fitted Dunlop SP300E's and they have travelled 70,000k so far, with more to go. One thing I am surprised with this car is the tyre life?

Anyway as to your question... "All HELP AND INPUT APPRECIATED" ...you seem to have received the answer that is beyond question here... >"The 28psi pressure was suggested by the RACV who I find are very adept at providing accurate and meaningful information."

Damn... just a thought .. another subject, which tyre brand is best and why?... noooooooo noooooooooo :nopity:

EDIT...

Just remembered a whisper heard recently.. tyres over a certain age limit regardless of tread remaining will not pass rego. Aparently they have found that old tyre casings deteriorate over time and are more apt to fail. So fitting the unused spare from grandmas car boot may be a no-no?

More here...

Rotten spares

Tires age and degrade over time even when they are not in use. Spare tires, which look perfectly fine, but are several years old, can fail with just a few days of use. Heat and sunlight slowly harden the rubber and the steel inside of the tire can corrode. When tires are replaced, the spare is often skipped, and when put into use in an emergency may be much older than the other tires on the vehicle. Drivers cannot tell how old their tires are because, in the United States, manufacturing dates on tires are printed in a code which the average consumer does not understand.

Edited by camfan
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2008 ACV40

I use 36 PSI on front, 34 on rear.

I've noticed that after a service, the Toyota guys fill the pressue up to about 35.

I've also read elsewhere that recommended pressure on the placard is too heavily influenced by comfort(ie. to sell the car), and that a higher pressure means better fuel economy, more road contact (ie. safer) and longer tyre life.

My neighber is over 60, he has his Aurion at 28 PSI because he values comfort, he had a Cressida before that, so that's the kind of driver he is (I'm late 30's if it makes any difference)

Cheers

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2008 ACV40

I use 36 PSI on front, 34 on rear.

I've noticed that after a service, the Toyota guys fill the pressue up to about 35.

I've also read elsewhere that recommended pressure on the placard is too heavily influenced by comfort(ie. to sell the car), and that a higher pressure means better fuel economy, more road contact (ie. safer) and longer tyre life.

My neighber is over 60, he has his Aurion at 28 PSI because he values comfort, he had a Cressida before that, so that's the kind of driver he is (I'm late 30's if it makes any difference)

Cheers

My Aurion is at 39psi front and 37psi back

Putting tyres at 28psi will feel better but that's way too lower for my liking. Your grip and braking will be badly affect and also the wear of the tyres.

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another thing to also take into consideration is the weight of the engine between cars. for example, between the 2az and 1mz there's from memory around 50kg different in the engine itself, let along the drivetrain.

i kept my tyre pressures at 37psi on the front and 35psi on the rear (thats in an 05 v6 sportivo with 205/60/16s), which i found quite comfortable. anything lower on the front, the weight of the engine on the front wheels made the tyres look like squashed marshmallows.

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  • 3 weeks later...

Hi just on the tyre pressure topic I have some experiences with my 2002 camry csi.

I tested the car in the toyota dealership; understandably it went very smooth,quite,felt like the suspension and tyres have dampped everything out but the car was felt neverthless lack of responsiveness.------just like you commented the dealership decreased the pressure to maximise the comfort side of the car

after the purchase, I checked all four tyres, fronts were 28psi, rears were 29psi.

next day I pumped them up to 38psi....well I did not enjoy the ride afterwards because the town I am living is an rural town, the roads are not entirly smooth, it was bit too rough for me.

I backed the pressure to 34psi front and rears and it works for me.

tyres are Bob Jane all rounder brand new.(205.65 15r).

Bob jane tyres are resonable preformer for the price tag. they do a good job on dry road with a careful driver but not in a wet condition or carry bit speed going through an roundabout....

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  • 3 weeks later...

It is best to inflate anywhere from 32psi to 34psi. Personally, I prefer 34psi. Most Camry's have comfort-biased supsension, so you can afford to have higher tyre pressure (with accompanying fuel saving and tyre wear benefits) without much loss of ride quality. I have never driven a Sportivo or Azura, so cannot comment on those sports-tuned models, however.

If you are driving a Camry (or really any car) with tyre pressure below 30psi the handling would be pretty dismal (if you care about such things - I am sure 99.9% of motorists don't).

Mr Toyoda.

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