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Wheel & tire size change - quieter ride

Discussion in 'Gen 2 Prius Accessories & Modifications' started by Wooster, Nov 12, 2017.

  1. Wooster

    Wooster Junior Member

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    Greetings from the UK! I've a 2005 with a modest 75k miles on the clock.

    I am cursed (?) with sensitive hearing and have applied lots of sound deadening products to my car with success. Tire roar is (now) almost non existent. However, I'm now very aware of a 'booming' noise whenever the car goes over a bump in the road. Road seams etc. (I'm guessing the 'booming' noise was previously masked by the tire roar.)
    All European cars (like mine) were all fitted with 195/55/R16 tyres and wheels. I've seen many USA cars specified with 185/65/R15. Smaller wheels and taller side walls - which I've been told will reduce the 'booming' noises in the car as there is a larger side wall to flex and absorb the shocks from the road. Put the numbers into here and it shows they are compatible. Tire Size Comparison

    Does anyone have any experience of a Prius with these different tires and wheels?
     
    #1 Wooster, Nov 12, 2017
  2. 69shovlhed

    69shovlhed Surly tree hugger

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    any econobox is gonna have a noisy ride. narrower tires are not gonna handle as well either. quality tires like Michelin will definitely be quieter than cheap crap tires. if handling isn't important to you, you could buy smaller wheels and taller tires, but I'd bet you will still hear the same noise over bumps. however, since the 185/65r15 tires that come on us base models are too small for the speedo to read correctly, it could be that a slightly taller tire would be a good idea for you. I run 205/60r15 michelins on my wife's car, which are a bit taller than oem so the speedo is more accurate, but I can't say that noise is any less over bumps. they are definitely quieter than the ecopias on my car. I won't be buying those again.
     
    #2 69shovlhed, Nov 12, 2017
  3. 05PreeUs

    05PreeUs Senior Member

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    Unless you value fuel economy over the noise reduction, decrease the tire pressure as much as possible; down to door sticker numbers if higher. Tire pressure has a big impact on ride harshness, noise and tread life.
     
    #3 05PreeUs, Nov 12, 2017
  4. Wooster

    Wooster Junior Member

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    Yes, totally agree with you about quality tires. Don't know if they're available in the USA, but I've fitted Michelin Cross Climate tires. Quietest I've ever known.

    My experience with 'smaller-wheels-taller-tires' comes from test driving a smaller Toyota. Resonant boom from the 55 section tyres, totally removed on the model with the 65 section tyres. But, I can't drive a an 04-09 Prius with 65 section tyres as they don't exist in the UK.
    I know 'booming' was an issue in the 04-09 Prius as the 2010 Prius Media Review said (on page 26) that the new Prius: "had interior booming levels decreased... with new material to absorb sound ..."
    Just want someone who HAS driven an 04-09 Prius with 55 and 65 section tyres - to know if changing my car would be a waste of time.

    Tire pressures: I've experimented with lower tire pressures - and run lower than the numbers on the door sticker. (But only for a short distance.) I think it helped reduce the 'boom' but it's difficult to be certain - it is so subjective!
     
    #4 Wooster, Nov 14, 2017
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