Your coin must be dated 1945, Tolar. The United States of Mexico (Estados Unidos Mexicanos) started issuing coinage in 1905.
Most dates of this coin are worth very little -- less than $1 US in worn condition. The piece shown in the picture has a numismatic grade around Extra Fine (XF) to Almost Uncirculated (AU); it is well preserved. If Tolar's coin is in as good shape as the picture, the $8 figure is a good estimate of catalog value. Here are typical values for these coins:
ALL DATES EXCEPT AS NOTED BELOW:
worn: less than $1 US dollar catalog value
average circulated: less than $1
well preserved: $1
fully uncirculated: $8
Some coins are worth slightly more. All values below are for coins in well preserved condition.
IF YOUR YEAR IS NOT MENTIONED BELOW, IT'S A COMMON YEAR - SEE VALUES ABOVE
1943 and 1945: $3 when well preserved
1951 and 1952: $8
1955 with teeth around letters on front (eagle side): $7
For a definition of 'catalog value,' use our Terminology page.