Gas -- Centre is spelled correctly (at least in every English speaking country I can think of except for the good ole US of A). Just like theatre, metre, centre, colour, whilst, etc. You might want to check the spelling of "sergeant" though ...

Considering it is a *World Wide* Web, and that we have a lot of Canadians, Aussies, Kiwis and Brits using (and contributing) to the site, I thought it would be a nice nod, as it were, to our Commonwealth brethren.
The trucks this site covers may be United States in origin, but the appeal and hobby is literally world wide. And that's a good thing.
And a very happy, if belated, Australia Day to ya, Mate!
Regards,
John