Have you done any search engine optimization? For example, I think it would good to be found in Google when someone types "saving gas". The title of the index page now reads "helping you save at the pump". This is good for a search term like 'save at the pump". I feel it is more likely however that a search term would be more "saving gas", "how to save gas", "gas saving tips".
Maybe try the index page with "Saving gas at the pump" Or "saving gas at the pump with these gas saving tips".
The index is just one page. The great thing about a forum is that there are many pages that could all be used to be aimed at certain key words you want to appear under when someone is using Google. You could do a rotation system with 20 search terms that are important to Gassavers.org. These search terms could then be added to the title. The title if this thread could read "A blatant plea for help - best gas saving tips". Together with every one of the 20 search terms you make a short text that has the chosen search terms in them. It is just meant for the search engine but to not make it look weird make it readable for readers. Put this text somewhere on top of the page so the spider sees it fast (gives you extra points), like above where you now have the ad to donate to Gassavers.org.
If enough people donated (yes, I am gonna do it as well) you could even think of running a Google AdWords campaign (I'd volunteer for it). That's my 2 cents
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