Yes the Bentley will do more than 245. I have not messed with it for a while but had it up to 247 the last time I had it out and the #1 times are hitting 248 in it.
I have a couple of Speed 8 tunes on my storefront for oval tracks, namely Motegi and Indy. There are more than one Indy tune there, Ironically the slower one is the highest rated with the most downloads but if you read the description you will see that the later version is faster.
It has been a while since I drove it but I am thinking it was hitting 246 on Indy. You could look at my replay to see for sure but that tune is the one I used.