The clock is ticking on a decision whether the Nissan and Mercedes teams will be allowed to run the E70 ethanol fuel for the endurance races.

Both teams ran the blend as a trial at Winton recently after gaining tacit approval by the entire V8 Supercars grid.

However disharmony among the teams remains following the trials of the E70 blend (70 per cent ethanol 30 per cent unleaded) on three cars including the Norton Nissans which completed a one-two result at the hands of James Moffat and Michael Caruso in the Saturday race at Winton.

There also remains conjecture over what benefits the E70 fuel, a reduction over the regular E85 ethanol mix, provides with a rival team claiming to have tested the fuel and for it to have returned a small horsepower gain.

Engines from Erebus (which ran E70 only in Maro Engel’s Merc on Friday and Saturday at Winton) and Nissan were supplied to V8 Supercars in the lead up to the Winton round for testing.

Both powerplants were put on the V8SC control engine dyno using both the E85 and E70 in direct comparisons.

V8 Supercars is yet to hand down a decision on whether it will approve of the use of E70 for Nissan and Erebus with the countdown to Sandown drawing near.

Given that E85 is the control fuel under the 2013 sporting regulations it would seem a remote chance that the sport would suddenly change the rules midstream to accommodate a fuel change.

Erebus team manager David Stuart says the only way his squad can achieve parity for the long distance races is for a concession to run the E70 mix.

“E70 is what we are looking for to be on parity with the Ford and Holden engines or the two-valve push-rod engines,” Stuart told Speedcafe.com

“For us the only solution going into the endurance races to have parity is to run E70 on all three cars.

“It’s the only solution that allows us to take advantage of the fuel windows that the two-valve engines can do and also the refuelling time.”

According to Stuart, the AMG Customer Sports-sourced engines consume seven per cent more fuel than the two-valve engines going on a lap per lap basis.

“All we can do is to supply them (V8SC) with as much information as we can and work with them in the process to try to achieve an outcome that is suitable to us and the category,” Stuart said.

It remains unclear as to when a decision is likely to be handed down.