The 245/35/19 would probably fit with less issues. The 245/35 IS taller by .5" but it would be stretched on the 9.5" rim. With the 245 you'd have nearly .5" smaller section width on each side of the rim (nearly 1" overall).
The taller overall size of the 245/45 will make it close in fitment compared to the 265 when it comes to rubbing the liners..

 

So you think a 265 will work best.... Ok i'll look into tires in that size.

 

Ok did some research ....

I pull up the specs on the tire manuf. sites and go the over all diameter and width

275/30/19 Overall Dia: 25.6 Overall Width: 10.7
265/30/19 Overall Dia: 24.5 Overall Width: 10.6

Now on my old 19" wheels I had a set of Khumo MX 245/35/19

245/35/19 Overall Dia: 25.8 Overall Width: 9.8

^these tires rub ever so slightly on full crank on my 8.5" width rims and +29 offset ..

Now my new rims are 1" wider with +30 offset so that mean that they should be stick out about 1/2 more then the old set.

Now this is where Im racking my brain .... if the 245/35.19 rubed a slight bit ... going with the 30 series will improve this becuase the over dis will be lower, but isnt the added width and the 1/2" more in wheel size going to factor in when turning???

 

Either one will need some finnesse, but at least at the end of the day the 265/30/19 will give you the same overall diameter and more rubber on the ground...assuming you can get a decent tire in that size...

Michelin Pilot Sport Cups come in that size...too bad they are $368/ea from tire rack though...

 

So offset isnt really a concern? its more over all diameter right ?

See I did a quick diagram to get a visual for my self:



Changing the offset only will vary where on the fender liner it will hit (that is if it rubs). For some reason I thought pushing the tire out gave it more clearance ... but this diagram help me figure that out that I was worng.

 

I think im going to try the 275/30/19 as its about 10mm wider and 5 mm taller over my track wheels and tires ... so really thats only about 2.5mm taller per side and 5mmout more from where it currently is..

 

Offset of course plays a roll. But you had 265/35/18 in there correct? With the same offset, you should be able to put 265/30/19's and have them act no differently since they effectively fill the same space as far as wheel wells are concerned.

 

No I didnt ... my 265/35/18 are with a +15 in the front and the new 19"rims will be +30

Offset really dosnt play that much of a roll .... look at the diagram I made ...


For example if the tire rubs a full tilt the inner liner with a certain offset and then I change the offset to be higher ... there for pushing the wheel back .... all it dose is change where on the inner wheel well it rubs ...

Offset may come into play when looking at height and the top of the fender ... but since I am already running +15 in the front going to a lower +30 shouldnt be an issue as Im moving the wheel inward ... I guess the main thing is to check the clearance between the back side lip of the rim compared to the suspension ... I dont want to rub the suspension with a +30 and larger tire.