Of the nearly 300,000 Utahns affected, the switch would save many of them money. But some would pay more, according to figures compiled by county assessors. Moreover, if the calculations are wrong, the change could end up costing homeowners and businesses by automatically boosting real estate property taxes.

Members of the Revenue and Taxation Interim Committee unanimously endorsed draft legislation Wednesday to make the change. The action gives the bill momentum for action in the regular session of the Legislature, beginning in January.

Automobile and light truck owners in Utah experienced a similar change, from a value-based tax to an age-based fee, in 1998. That switch brought initial protests because residents with older, low-priced models paid more, while owners of newer, luxury vehicles saved several hundred dollars apiece. But county tax collectors say the fee system has gained widespread acceptance because it simplified registration and capped the car and truck fee at $150.

Under the proposed legislation, ATVs and snowmobile fees would top out at $45; motorcycles at $95; travel trailers, $175; campers and tent trailers, $70; boat, utility and horse trailers at $30; jet skis, $55, motorboats of up to 14 feet at $10; and motorboats 27-30 feet long, $700.

Although figures used to prepare the draft bill indicate most people affected would save money under the fee, people owning some categories of property would pay more. For example, owners of newer motorboats in the 15- to 18-foot range would pay between $10 and $40 above their current tax bills.

Overall, the fee scheme is designed to produce the same amount of revenue as the current tax. The danger to homeowners arises if fees do not produce the amount of revenue estimated. Then, the difference would be made up with property tax increases on residential and commercial real estate.

One group that has been clamoring for a change from taxes to fees is motor home owners. They say they are being gouged by Utah's current tax structure. But motor homes are not included in the draft legislation.

"It's really frustrating now that the tax is forcing me to decide whether to move out of Utah," said Darwin Tobler, 66, of Sandy.

Tobler, who purchased a motor home last year, faces a tax bill of $2,300 - more than he pays on his home. He said he could register the vehicle in Montana for $300.

Rep. LaWanna Shurtliff, D-Ogden, is working on a plan to ease the burden on motor home owners but has yet to present draft legislation.