Ethanol Boosting Systems, LLC v. Ford Motor Company, Appeal Nos. 2024-1381, -1382, -1383 (Fed. Cir. Dec. 23, 2025)

In its only precedential patent opinion last week, the Federal Circuit affirmed inter partes review decisions invalidating all challenged claims of three automotive patents owned by the Massachusetts Institute of Technology.  The Patent Trial and Appeal Board had initially declined to institute review, but on petitioner Ford’s request, waited over 15 months to reconsider that decision while the parties appealed a co-pending infringement case against Ford by MIT and its licensee.  Among other things, the Court in this appeal rejected appellants’ argument that the Board had impermissibly “stayed” rehearing of Ford’s petition, finding their arguments amounted to little more than a challenge to the propriety of the Board’s institution decision, and thus barred under 35 U.S.C. § 314(d) (providing institution decisions are not subject to appeal).  The Court also affirmed the invalidating decisions on the merits.

MIT’s U.S. Patent Nos. 10,619,580, 10,781,760, and 9,708,965 are directed to methods of mitigating “engine knock” in internal combustion engines, and are administered through MIT’s exclusive licensee Ethanol Boosting Systems (EBS).  As relevant to this write-up, the patents describe “direct injection” and “port injection” fuel management systems that work in tandem to provide beneficial ratios of fuel to an anti-knock agent at various torque and pressure levels.  EBS and MIT sued Ford in October 2020, and Ford responded by filing the IPRs at issue in this appeal.  In March 2021, the district court issued its claim construction ruling, agreeing with Ford that the claims require different fuels for the direct and port injection systems.  A few months later in July 2021, the PTAB denied institution of Ford’s petitioned IPRs, relying on this narrow, “different fuels” aspect of the district court’s construction.

Meanwhile, EBS and MIT had stipulated to non-infringement so they could appeal.  In August 2021, Ford requested rehearing of the Board’s decision denying institution of the IPRs, but asked the Board to delay reconsideration until after Federal Circuit considered the parties’ claim construction arguments in the district court appeal.  Nearly a year later in July 2022, the Federal Circuit vacated the district court’s non-infringement judgment, finding the “direct” and “port” injection systems did not require different fuels.  A few months after that, in November 2022, the Board reconsidered its institution decision in Ford’s IPRs; instituted review based in part on the broader construction permitting like fuels; and ultimately found all challenged claims to be invalid over the prior art.

On appeal, MIT and EBS argued that the Board had impermissibly “stayed” its reconsidered decision for over a year, which exceeded its statutory authority to administer IPRs and required vacating the proceedings entirely.  The Federal Circuit rejected this argument, noting that there is no statutory or other deadline for deciding rehearing petitions, and so there was nothing for the Board to “stay” in the first instance.  Moreover, 35 U.S.C. § 314(d) renders decisions whether to institute “final and nonappealable;” the Federal Circuit had previously interpreted that to apply to reconsideration decisions; and the Court found appellants’ challenge to fall squarely within the scope of precedent prohibiting review of such determinations.  The Federal Circuit allowed that review may be possible in light of constitutional or limited other challenges, but that appellants had waived any such challenges in this case.

The Court went on to affirm the Board’s final written decisions on the merits.  Among other things, the Court rejected MIT and EBS’s argument that the Board was required to defer to a non-appealed portion of the district court’s claim construction as “law of the case,” noting that even if the construction was controlling in the district court proceedings, appellants cited nothing to suggest that it should be controlling in a different litigation before a different tribunal, and that the PTAB was in any event not required to consider claim construction arguments not raised by the parties.  The Court also found the Board’s findings on the teachings of the prior art and motivation to combine to be supported by substantial evidence.

The opinion can be found here.

By Jason A. Wrubleski

This article summarizes aspects of the law and does not constitute legal advice. For legal advice with regard to your situation, you should contact an attorney.