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For MPG do front tires matter more then rears?

Discussion in 'Gen 3 Prius Fuel Economy' started by cyclopathic, May 18, 2011.

  1. cyclopathic

    cyclopathic Senior Member

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    Why front tires matter more then rears when it comes to bottom line MPG?

    Is due to weight distribution? more load due to braking and being FWD?

    on FWD front tires usually wear faster then rears b/c of load as 60% of weight rides on front tires, all acceleration and majority of braking done by front. Probably more so on Prius as all regenerative braking done by front only. Usually there is enough tread left on rear (at least 40%) when front is gone.

    Obviously replacing all 4 tires with LRR would be the best.. however the question becomes if you replace 2 front tires only with LRRs but leave old rears would it improve MPG more then if you replace just rears?
     
  2. BrettS

    BrettS Active Member

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    I'm not quite sure what you're asking or why you're thinking that front tires matter more than rear tires? I don't think I've seen any posts that suggest that is the case. Can you clarify your question a bit?
     
  3. WE0H

    WE0H Senior Member

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    We had a rental Gen III a week ago that had regular all season rear tires and it got roughly 10 mpg less than normal. LRR tires on all 4 corners is a must.

    Mike
     
  4. F8L

    F8L Protecting Habitat & AG Lands

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    I don't think it is going to matter since you need all four tires in contact with the ground at all times so it's kinda like the weakest link in the chain type of thing.

    Now if you have bad tires in the front that cause you to make steering corrections constantly then the front tires may matter more but having those tires in the rear will still cause much friction so your MPG will suffer either way.

    Ultimately it is the rule that you put the tires with the most tread in the rear regardless of drive type (FWD/RWD/AWD). So if you are contemplating only purchasing two new tires then those should go on the rear of the car. I cannot see any other reason for your inquiry other than that.
     
  5. cyclopathic

    cyclopathic Senior Member

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    just posted clarification in OP.
     
  6. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Sounds as if you never rotate your tires as you should.
     
  7. F8L

    F8L Protecting Habitat & AG Lands

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    It would be unsafe and that is all that really matters.

    You could do it your way but I don't think there will be a measurable difference in MPG. At least none in which you could measure without a very controlled experiment.
     
  8. WE0H

    WE0H Senior Member

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    Best thing is to rotate the tires at every oil change so when it becomes time to replace tires, you put 4 new tires on. Tires have date codes and should be matched for best performance. Ask Tire Rack to match date codes on your tires when you order them.

    Mike ;)
     
  9. nickfromny

    nickfromny Member since 2007

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    2lbs more in front enhances handleing in Prius. Our car can behave badly and oversteers if loaded to max. 2-4lbs more in front tires vs. rears calms this issue down and helps enduces understear. (oversteer=car feels twitchy)Tire presure is most important handleing modification one can make to their car. Try to always put heavy load infront of rear axle and down low. This issue is due to heavy battery pack in back on top of rear axle and billboard cross wind profile.
     
  10. richard schumacher

    richard schumacher shortbus driver

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    Can you run faster if your left leg is broken, or your right leg?

    All four tires matter for fuel economy. *Safety* is the reason for putting new tires on the rear first, if you buy two tires at a time. New tires on the rear reduce the chances of fishtailing.
     
  11. mad-dog-one

    mad-dog-one Prius Enthusiast

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    I think the analogy is more like ... 'A broken hind leg won't slow you down if both front legs are working.'
     
  12. cyclopathic

    cyclopathic Senior Member

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    It is not a question of broken leg but the question of a different shoe?

    appreciate the concern but there is no issue with safety, rear tires have more then 50% tread left. And being a FWD and with amount of understeer Prius has you don't have to worry about fishtailing. If you can make yours fishtail pls post video. :cheer2: