Designed to meet CSA B149.
- GTI Classic -- Either a "on" or "off" state with a set fuel substitution percentage over a set load range.
- GTI+ -- Continuous substitution with variable fuel substitution percentages over the entire load range.
Both the GTI Classic and GTI+ allow for operation on gas up to a maximum of 70%* of the usual fuel required to maintain the desired speed and load.
*Based on several factors including: fuel quality/BTU rating, engine make/model, engine health and load, and environmental operating conditions.