will '65 tires fit instead of '70?

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canuguy - 26 Sep 2004 23:20 GMT

I currently have OEM sized p185/70/14 tires on my '95 Accord.
I can get a real cheap set of used p185/65/14 tires from a friend. Will
these fit??

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Elliot Richmond - 26 Sep 2004 23:26 GMT

>I currently have OEM sized p185/70/14 tires on my '95 Accord.
>I can get a real cheap set of used p185/65/14 tires from a friend. Will
>these fit??

Yes and no. The tires will go on the rims, but they will have a lower
sidewall depth (that's what the 65 refers to) which will make the
overall tire diameter smaller. Since the overall tire diameter is
smaller, they have to go around more times to make the car go the same
distance. Your speedometer will read incorrectly, and your overall
gear ratio will be altered. This is not a good thing.

Hope this helps.

Elliot Richmond
Freelance Science Writer and Editor

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canuguy - 26 Sep 2004 23:36 GMT

Well, I'm not too worried about speedometer because my speedomoter doesn't
work:-) (Actually, I use my GPS as a speedomoter now and thus tire size
won't be a factor).
What possible problems would I have with "overall gear ratio" being altered?

P.S. They're winter tires and I'd used them driving back roads 80kms
(50miles) per day, but hardly ever long distance drives (we take the SUV
when travelling the long distances so I can lug all the other junk). My car
has around 300,000 kms and getting rough around the edges, so I don't mind
the minor things like I used to anymore...

>>I currently have OEM sized p185/70/14 tires on my '95 Accord.
>>I can get a real cheap set of used p185/65/14 tires from a friend. Will
[quoted text clipped - 11 lines]
> Elliot Richmond
> Freelance Science Writer and Editor

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Randolph - 27 Sep 2004 02:52 GMT

You will not get any problems. Acceleration will be a hair snappier, but
not enough that you'll notice it. Cruising at 70 mph, your engine RPM
will be 3.1% higher than before, but again, no big deal. Ground
clearance will be decreased by about 3/8"

> Well, I'm not too worried about speedometer because my speedomoter doesn't
> work:-) (Actually, I use my GPS as a speedomoter now and thus tire size
[quoted text clipped - 22 lines]
> > Elliot Richmond
> > Freelance Science Writer and Editor

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Elliot Richmond - 27 Sep 2004 04:22 GMT

>You will not get any problems. Acceleration will be a hair snappier, but
>not enough that you'll notice it. Cruising at 70 mph, your engine RPM
>will be 3.1% higher than before, but again, no big deal. Ground
>clearance will be decreased by about 3/8"

I agree this will likely cause no problems under the conditions the
original poster described, but it is not insignificant.

There is a web site that does this calculation very tidily (probably
the same one others have been using),

http://www.1010tires.com/TireSizeCalculator.asp

It recommends no more than 3%. So this switch is right at the maximum
recommended difference.

Elliot Richmond
Freelance Science Writer and Editor

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Aron - 10 Oct 2004 06:16 GMT

You will drop your top speed and likely decrease your gas mileage - more
tire RPM = more engine RPM

Aron

> You will not get any problems. Acceleration will be a hair snappier, but
> not enough that you'll notice it. Cruising at 70 mph, your engine RPM
[quoted text clipped - 27 lines]
> > > Elliot Richmond
> > > Freelance Science Writer and Editor

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Bill - 27 Sep 2004 01:29 GMT

>Yes and no. The tires will go on the rims, but they will have a lower
>sidewall depth (that's what the 65 refers to) which will make the
>overall tire diameter smaller. Since the overall tire diameter is
>smaller, they have to go around more times to make the car go the same
>distance. Your speedometer will read incorrectly, and your overall
>gear ratio will be altered. This is not a good thing.

By a whole 3.1%!
You'd probably not notice the difference.

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