8s up front help

[band1t]

Thanks everyone for the help on the rear rim and tire set up turned out great (275 40 rear)
Now time for the fronts

runnin a 17x 8 wide rim
4.5 BS on the old 1979 T/A

I was told a 235 40 or 245 40 up front
but I dont want the bead of the rim to show
so do they balloon over the bead a bit
maybe go up on the sidewall to a 45 range of tire
or should I go up to a 255 40 or is that to big up front

thanks for the help

[mc84_zz4]

The 245/45/17 is the best match for the 275/40/17, they will have the same proportions and sidewall height.
If you ran a 255 on the 8" front wheel; it will look fatter than the 275 tire on the 9.5" rear wheel.
A 235/40 would appear small IMO, I prefer getting more footprint under that heavy front end.

Here is a 245/45/17 on 17x8 4.5 bs front (rear: 275/40/17 on 17x9.5 - courtesy of another member at MCSS.com)
https://static1.pt-content.com/images/pt/2011/05/P6060912-1.jpg
Here is a 255/45/17 on 17x8 4.5 bs front (rear: 285/40/17 on 17x9.5)
https://static1.pt-content.com/images/pt/2011/05/IMG_0285jpg_Thumbnail1-1.jpg
HTH

[Tony_SS]

I disagree.. some 245/45 are actually taller than a 275/40 (depending on manufacturer) so I would run a 255/40 up front.

[mc84_zz4]

Not to argue, I'll go ahead that some 'could' but it would be in millimeters, imperceptible.

Here is a link of 245 and 275, the math arrives at identical heights (25.7")
http://www.rimsntires.com/specs.jsp?item=Wheel-Tire size comparer&sw1=245&ar1=45&bd1=17&rw1=8.0&et1=0&sw2=275&ar2=40&bd2=17&rw2=9.5&et2=-6&text1=&text2=

Here is a link of 255 & 285, the front is 26.1" the 285/40/17 is 26.0" (technically less than 26.1, 25.4 mm = 1"; diameters are exactly 662 mm vs 660 mm)
http://www.rimsntires.com/specs.jsp?item=Wheel-Tire size comparer&sw1=255&ar1=45&bd1=17&rw1=8.0&et1=0&sw2=285&ar2=40&bd2=17&rw2=9.5&et2=-6&text1=&text2=

The 255 on an 8" would have more pronounced tire bulge than the 275 on the 9.5" rears...

[Tony_SS]

Reread the OP. He says 255/40 not 45.

The 255/40 is 25" tall compared to the 275/40 being 25.7"

And check Nitto 555 specs. The 245/45 is taller than the 275/40-17. Yes it maybe only an 1/8", but when the rear tread wears down, then the fronts will be closer to 1/4" taller than the rears. Not something that I'd want.

[mc84_zz4]

Tony,
Technically you are correct, but you are making a point over 8/100s (.08) of an inch, imperceptible, not 1/8" (.125);
which even then, we are splitting hairs here.
2 stacked Dimes measure +/- .09", 1 Penny + 1 Nickel stacked are +/- .125

The overall diameter on the Nitto site specs are:
245/45/17 - 25.67"
275/40/17 - 25.59"
http://www.nittotire.com/index.html

The only help I was trying to provide was a visual example of what the sidewall bulge appears
to look like, since that was one of the main questions the OP had asked, and how it related
to covering the wheel lip.

The 255 in either profile (40 or 45) would appear 'fatter' on the sidewall than the 275/40 on the rear.
That would look goofy having a 'fatter' front tire than the rear - IMO.
A 235 fits best on a 7" wheel IMO, looking stretched on an 8" wheel (depending on brand), but it would tend to show more wheel lip.

To the OP: HTH

[Tony_SS]

A 235 fits best on a 7" wheel IMO, looking stretched on an 8" wheel (depending on brand), but it would tend to show more wheel lip.

To the OP: HTH

I think youre right about the 255's bulging too much on an 8" wheel.

The OP should tell us what tires he's running on the rears.. the would help. But I would do a 235/45 since they're 25.3 tall and call for an 8" tire.

235/45/17 25.28" tall, fit on 7.5(8.0)9 wheel

That why the front tire is a tad bit shorter than the rear. Something about having a taller front tire just bugs me. Even if its just a fraction of an inch.

[band1t]

On a 35 mph turn with some body roll would a 245 45 rub
and even just a hard turn
or is it free wheelin no rubbin on that monte carlo

[mc84_zz4]

The 245 on the Burgundy Monte have no rubbing, it has 2" drop spindles, and still the original
coils, which are being replaced with higher rate coils.
Only on very sudden dips at high speed (more like 50+ mph) the inner fender gets a bit of a rub, but that is
due to the drop spindles with soft stock coils.
No rubbing on full turn, speedbumps, or most road dips/bumps, or 'spirited' driving.