Updated

Struggling engine manufacturer Lotus released Bryan Herta Autosport and Dreyer & Reinbold Racing from its IndyCar engine contracts Tuesday.

The release clears the two teams to cut new deals with powerhouse manufacturers Chevrolet and Honda, and leaves Lotus with just three cars spanning two teams. BHA had already said it would not take Alex Tagliani to Sunday's race at Brazil, while DRR driver Oriol Servia will make his final start with a Lotus this weekend.

Neither team had a new engine deal to announce Tuesday.

"I ran cross country in high school, but I am not quick enough to push the car around the track myself. We need an engine," Herta said. "Obviously, if we get one, it's going to be either a Chevrolet or a Honda, but we don't have anything yet. It was a little bit of a leap of faith, but that's why it's really good it was done amicably between teams and IndyCar and Lotus.

"It puts us all in a good position to grow."

Lotus, the third and final manufacturer to enter IndyCar this season, has not been competitive through the first three races. Reliability, a lack of horsepower and engine availability have been overwhelming issues, and the highest-finishing Lotus driver so far was Sebastien Bourdais' ninth-place finish at Barber for Dragon Racing.

"It was clear from the start that the 2012 season was going to be a huge challenge as Lotus debuted its IndyCar engine, but it was a challenge that Lotus was determined to meet," Lotus said in a statement.

Letting BHA and DRR go probably helps Lotus, which has not been able to build enough engines fast enough and may be able to catch up through a reduced workload. It's teams have been severely restricted in testing this season because of a lack of engine availability, and no Lotus teams participated in the open test at Indianapolis Motor Speedway this month.

"Lotus has acknowledged that whilst the engine has demonstrated a lot of promise, minimal testing has resulted in reliability issues," the statement said. "Having now had the experience and feedback from the first three races of the season, Lotus undertook a strategic review of its position to decide what course of action would be in the best interests of IndyCar and the teams it supports."

Tagliani has failed to finish the last two races, and the team decided late last week not to travel to Brazil.

"The situation had become very difficult for everyone, and we hope a more streamlined and focused program for Lotus is going to help them spend their money on resources and development," Herta said. "Clearly, we all felt there was a change needed to allow everybody's programs to progress. The timing of this just made sense, coming up to Indy, that's the big one, that's the one everyone wants to position themselves for."

Herta won the Indianapolis 500 last season with the late Dan Wheldon.

Servia, meanwhile, has had three engine changes through three races already this season, and each one earned a 10-spot penalty on the starting grid. IndyCar has also said teams are limited to just five engines all season before they will be again penalized.

The strict rules are in place to protect the engine builders, who have given IndyCar multiple engine competition for the first time in seven years. But IndyCar is adamant it will help the engine manufacturers keep costs down to make it viable for them to compete.

But Lotus has struggled to get to the same level as Chevrolet, winner of the first three poles and races, and Honda, which has three second-place finishes this season.

"Lotus in IndyCar is like David versus Goliath," said Claudio Berro, director of Lotus' motorsports group. "We are and always will be a niche British sports car company built for the few not the many. That said I'm delighted with our solution and I can assure everybody that the actions were taken after careful consideration and will assist in ensuring the brand's high racing ambitions and the high expectations of the IndyCar community are realized."

Lotus' entry has been somewhat comical at times, particularly the season-opener, when Bourdais had conceded he would not be able to compete because Lotus did not have an engine for him. Instead, the backup for Servia was transferred to Dragon the night before the first practice, allowing Bourdais to race in the season-opener.

With BHA and DRR moving on, Lotus will now field engines for Dragon drivers Bourdais and Katherine Legge, and Simona de Silvestro of Lotus HVM Racing. In comparison, Chevrolet has 11 drivers and Honda has 10 — before either picks up BHA or DRR.

In addition to finding a new engine manufacturer, DRR also will have to go through another rebranding. It changed its name from Dreyer & Reinbold Racing to Lotus DRR at the start of the season, and adopted Lotus' factory black and gold colors for its cars and uniforms.

Dennis Reinbold, co-owner of DRR, said an announcement on the rest of the season is coming.

"Our focus is on the Brazil race and we are still a part of the Lotus team," Reinbold said. "We are excited to go down there. We wish Lotus all of the best going forward. We are in the midst of finalizing our future plans and we are talking to the series to conclude that process."