iPhone Is all tethering equal?

Yes.

 

I don't think this is accurate. The ipad will use a lot of mobile webpages and thus use less data that a pc.

 

Huh? What's coming down from the website doesn't change based on the receiving device. Yes, it will be formatted differently, but that's not going to add significantly to what's transferred.

 

I've heard otherwise. The foxnews website for instance that you would view on a pc will use more data from the iPhone while tethering then say the mobile version you would see on an ipad. Won't it?

 

Yeah, different websites react or push pages different depending on what device you're on. Unless you force desktop mode for all the websites across all devices.

With comparing the iPad and laptop. You have to understand that there is "real" multi-tasking with a computer, where you can have multiple programs running. For the iPad (including iPhone) there really isn't "real" multi-tasking.

Such as right now, I have the twitter application on my macbook pro open while web-browsing. The twitter client on my macbook pro is constantly pushing new tweets to me that are appearing on my timeline, even though my main focus is in Safari, while I have another Safari window streaming video. On the iPad, if I put the twitter client to the background, while my main focus is in the Safari app. I would not be getting new tweets in my timeline pushed to me constantly. I may get a notification if I'm mentioned in a tweet, but that is totally not multi-tasking. And I definitely wouldn't still be getting a streaming video from "window" of Safari (maybe audio, but not video)

 

Given the website is pushing the SAME version then the data will be the same. But websites tend to have mobile and desktop version therefore the mobile version uses less data because it's usually less 'rich'.

So to answer OP, it's the same unless there's different version of the site.

Why are you bringing multi tasking into this? No one mentioned about it and you are explaining it when no one is wrong/misunderstand/asking it.