Clubjazz - Honda Jazz & HR-V Forums
Honda Jazz Forums => Honda Jazz Mk4 2020 - => Topic started by: Saycol on February 27, 2022, 01:49:43 PM
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The tyre pressure label on the driver’s doorjamb label tells me what pressure front and rear tyres should be inflated to. But this is the first car that I have owned that does not have a second set of higher pressures when driving fully loaded. Seems odd to me that the car’s optimum behaviour will be satisfied by one set of pressures whether being driven empty apart from the driver or fully loaded four up with a boot full of luggage.
The handbook has a paragraph for high speed driving tyre pressures (excluding the Crosstar!) but nothing else.
Thoughts anyone?
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I always increase the prescribed tire pressure by 0.3 bar/4.5 psi. Saves fuel and has little or no influence on handling and comfort.
Moreover, always ready for a fully loaded car! ;)
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Maybe the Crosstar is for looking at, not for actually carrying things. ;D ;) :D
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I have often run with +1 psi but much more and you can cause premature central tyre wear.
Just like under inflation causes outer edge premature tyre wear.
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On my last car there were actually 6 sets of pressures!
https://www.puretyre.co.uk/wp-content/uploads/2017/09/Volvo-V40-20550R17-Tyre-Pressure-Placard-768x310.jpg
Depending on how fast you were driving and what you were carrying, as well as if you wanted to save fuel.
As my loaded trips were a maximum of 25 miles I just left them at the standard pressure.
I’ve heard of Prius drivers using very high pressures to get a few more mpg, but likely not worth it as the tyres would wear out quicker in the middle.
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The days when manufacturers specified a fairly low pressure with the option of raising this for load or high speed is mostly going or gone . Manufacturers use higher pressures when testing to get the best possible fuel consumption and emissions results for official figures used by governments to set taxation and environmental classes etc.
So thats the pressure they must specify as standard . They can probably recommend settings higher than this as emissions will be better. But probably not lower although IIRC a while back I saw one car (I cant recall which) that did have the high pressure as standard, but mentioned a lower pressure that gives better ride comfort.
they may also have to sell the car with the type of tyre used for the tests. I think there is a car that just manages to avoid the london environmental zone charge on one of its tyre options but not the other.
Could be the reason that Honda cant approve the much more common 195/55R16 tyres for the crosstar ,even though they are a close equivalent.
Its quite likely the Jazz suspension is set up to perform best at this high pressure . Any reduction would increase fuel consumption and may be detrimental to the tyres and handling etc. Honda may see no need for a higher pressure option as its already quite high.
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I have often run with +1 psi but much more and you can cause premature central tyre wear.
I have been driving with a 0.3 bar/4.5 psi increased tire pressure since 2008. Tires always wore perfectly evenly (at least until now)...
Why would you increase 1 psi? Effect is nil, at most your TPMS warns you a little later in case of pressure loss.
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Thanks everyone for your replies. I certainly don’t want them under inflated and as I have a forthcoming long trip with full load, I will increase the tyre pressures slightly before setting off.
As I said in my original post, I have never before owned a car with a recommended single set of tyre pressures whatever the loading. My previous car (2020 Golf) and my wife’s 2016 Mini both have two sets.