I'm Sorry Fuelly Mobile doesn't feel as fast to you as the old version. We have it running as fast we can.
I know it seems like we simply updated the site to make it cool and shiny, but the new site is designed to work much better on mobile devices. One of the biggest issues it solved is that adding the app to your home screen means it can run more like a native app. Instead of opening new links in a new Mobile Safari instance, everything runs in the same window. That was a long standing annoyance with the older site.
The site also runs better for a wider variety of mobile devices. We still have some issues with Blackberry 5, but overall we're supporting a larger number of devices with the new version.
When we make changes we are thinking of helping the widest possible audience we can, but in the process some people aren't going to happy with the changes. It sounds like you're in that camp this time.
We've been talking about this and today we put in an option to remove all styling from the mobile version. So if you go to the mobile version you now have the option to click "Basic" at the bottom of the page to see the mobile site with minimal styling.
That should help if you're on an older device or a slower connection.
The mobile version stopped working for me, it just gets stuck on the loading logo right after I click on my car. But the link to the regular version at the bottom still works so I just use that instead.
Oddly enough, while not optimized for the small screen, the regular version seems to be less laggy on my phone.