speedometer question?
- Thread starter Cody_21
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As 1engineer stated...
Yes, your speedo will of course be off from what it currently is due to increased circumference of tires...that being said, it may be more accurate. I have almost 33's and now my speedo is closer to actual than with stock. I am now(according to GPS, stop watch and traffic speed monitors) +0 to +1 mph at 60. Before tires, I was -2 to -3 mph at same speed.
As for power, anytime you increase unsprung weight (heavier tires), your engine will need to work harder and you will feel "less" power. My tires are heavy, 61 lbs. My lift decreases aerodynamics. Is it noticeable? In my head, yes. Real world? Not enough to make a difference IMO (especially after adding new muffler and intake). Does my mpg suffer? Yup. But I didn't buy a 4runner for fuel efficiency.
Multiple threads address this in further detail. Searching more should yield further details.
Cheers.
Yes, your speedo will of course be off from what it currently is due to increased circumference of tires...that being said, it may be more accurate. I have almost 33's and now my speedo is closer to actual than with stock. I am now(according to GPS, stop watch and traffic speed monitors) +0 to +1 mph at 60. Before tires, I was -2 to -3 mph at same speed.
As for power, anytime you increase unsprung weight (heavier tires), your engine will need to work harder and you will feel "less" power. My tires are heavy, 61 lbs. My lift decreases aerodynamics. Is it noticeable? In my head, yes. Real world? Not enough to make a difference IMO (especially after adding new muffler and intake). Does my mpg suffer? Yup. But I didn't buy a 4runner for fuel efficiency.
Multiple threads address this in further detail. Searching more should yield further details.
Cheers.
Hellamatic
New member
To add to this, another reason power suffers is because you've effectively raised your gear ratio by adding larger tires.
As for mileage, it will plummet. I have no basis for judging a difference in my 4Runner (I added lift/tires before I picked it up from the dealer,) but putting 33x13.50"s on my Tundra took it from high teens/low 20s to around 10-12mpg
As for mileage, it will plummet. I have no basis for judging a difference in my 4Runner (I added lift/tires before I picked it up from the dealer,) but putting 33x13.50"s on my Tundra took it from high teens/low 20s to around 10-12mpg
flying fuzz
Member
I had about 4k miles before I put on 285/70/17 Cooper ATP and OME lift, mpg went from high 18's to mid 16's, speedo is off by about 2-3 mph.
uhmmm... hang on 1Engineer... Acceleration and torque will be less; the engine output will still be the same. So what is that.. a difference in HP at the fly-wheel versus HP at the wheels!?!
*Grin* .. yes.. I was, and still am, that obnoxiousness kid in class that keeps challenging the answer because i think there is more to it or simply because it's fun to play devil's advocate :lol: :reddance: :frisky:
And the OP can go here and check how much his speedo will be off: http://www.miata.net/garage/tirecalc.html
Okki
Last edited:
1engineer
Moderator
Yea I know I know. I have learned on here that this is NOT the sandbox I am accustomed to playing in nor are most of the kids here the same as the kids in my playground. Here I have to make assumptions based on incomplete data and as I have been cautioned many times in the past I have to play nice lol. The OP did not say if his speedometer would be less accurate he said "off a little bit." That means it did not have to be accurate to begin with just different after the bigger tires. On the power loss I had to pull a hair and make an assumption that he really meant "Less usable power at the wheel." I answered him as accurately as he asked the questions. You are of course correct that there actually will be no generated power loss from the prime mover just less usable power. :redbrick: (I don't use these little smiley things very often but the banging head against the wall is by far my favorite!) Okki, just you wait until you ask a question next time lol!
harper7
Senior Member
31's or 32's.....Not much at all on the speedometer as a new stock tire diameter is 31.6" on all the models.By the time the tread wears down it will be under 31".
Power loss depends on the weight and type of tread of the new tires.
What exact tires and size did you have in mind?