Vitantonio Liuzzi has played down suggestions that his Toro Rosso team enjoy an advantage over their rivals for using a V10 engine.
"They are just jealous. For sure it is always the same: people are trying to say things about the performance that we are doing," Liuzzi told autosport.com. "We have got our down side and up side.
"For sure we have a good side in the reliability of the engine in the races, but in qualifying for sure we will struggle. It seems the V8 will be much stronger, so you always have to take the good things and the bad things.
"We look good for the race but on Saturday it will be tough to follow the others."
Liuzzi's comments come after Mercedes motorsport boss Norbert Haug said Toro Rosso could be fighting for a podium finish next Sunday at the Bahrain Grand Prix.
"Toro Rosso have more horsepower - that is not a secret," said Haug. "It could be up to 10 percent more. They also have more torque. But I am not criticising that. They were strong in testing here and they can go for a podium here, I am convinced."
Liuzzi believes Toro Rosso are looking more competitive than they actually are because their rivals have detuned their V8 engines in order to avoid problems.
"I think it looks like that because many people are struggling with reliability," he said. "It seems like they are not able to finish a race distance so they have to push the power down, but I am sure with development they will make the car more reliable and we will struggle even more.
"It is looking positive for the first three races because they are looking very hot and this will be a negative point for the other teams but it is difficult to say how good we are, because in testing the V8 showed a really good performance."
Liuzzi's teammate Scott Speed said reaching the podium was not a realistic target, but claimed the team will aim to score a few points.
The American also admitted that if they reached the podium, a further restriction of their V10 engine would be fair.
"If we got a podium then immediately we will have a restriction on our hands which would be the right thing to do," Speed said. "I don't think a podium is something that we can realistically hope for, I think getting a few points is something that is more reasonable to expect."