LMP1 non-hybrids have been slowed ahead of next weekend’s FIA World Endurance Championship season-opening Six Hours of Spa, following Equivalency of Technology adjustments made to the privateer entrants.

The FIA’s declared EoT for Spa, which was released last week, confirms both a power and fuel capacity reduction to the non-hybrids since last month’s Prologue pre-season test.

It equates to roughly a 14 percent less available energy and a 6.9 kg decrease in fuel capacity per stint for non-hybrids compared to the configuration that was run at Paul Ricard.

The Toyota TS050 Hybrids, which per LMP1 rules retain the same performance levels as last year, has seen its 69 percent deficit to the non-hybrids in maximum fuel energy (MJ/lap) reduced to 49 percent for Spa.

That compares with the EoT for non-hybrids in post-Le Mans races last year, which had a 63 percent increase in fuel energy compared to the Toyotas and Porsche 919 Hybrids, which both ran in the 8 MJ Hybrid subclass.

LMP1 non-hybrids, which were permitted to run with 54 kg of fuel per stint at the Prologue, will now only be allowed 47.1 kg, with the Toyotas remaining at 35.1 kg.

The minimum weight of 833 kg for non-hybrids and 878 kg for the Toyota hybrids remain unchanged as well as the maximum fuel flow, although adjustments have been made to the size of the refueling rig restrictors for both types of technology.

The changes come in the wake of data collected by the FIA at the two-day test, which saw the pair of Toyota’s top the time sheets, but had been running outside of the EoT regulations.

It’s understood the No. 11 SMP Racing BR Engineering BR1 AER had set the quickest time at the Prologue out of the laps completed by cars in full conformity of the regulations.

With the FIA yet to release the EoT for Le Mans, it’s understood further adjustments can still be made in the run-up to the French endurance classic.