heres car 1 at the original size it was 2.57mb and after saving for the web it is now 1.00mb its width in pixels is 3072 and its height is 2304
its inserted into this post at the largest size
heres the same image at 800x 600 and after saving the original 512kb at 60 quality for the web the size became 120kb
From what I can see the size in the blog is not affected at first glance, however the option to zoom is available on the first image due to the size. There is a visible difference in the first full size picture which is a little clearer and the second one is a little less sharp and crisp. The problem is that the first image makes the blog take a lot longer to load and will swallow the bandwidth limit very quickly.
I would use the smaller image as web users don’t want to wait for ages for a picture to load and the amount of quality lost doesn’t warrant the size difference.