BNSF's hot Los Angeles to Chicago UPS train with GECX 2028 in charge races through Horseshoe Curve along the San Bernardino Sub.

Tier4 basking in the sun waiting to be serviced

GECX 2022 Tier 4 demonstrator unit passes under the hump bound for the fuel plant on a warm summer afternoon.

The Canadian National C701, led by two General Electric Demonstrator Units, pulls into the siding at Cruger, MS with 155 cars as it waits on a Southbound Rail Train.

The Canadian National C701, led by two General Electric Demonstrator Units, Departs the siding at Cruger, MS with 155 cars as it heads North to set out cars in Greenwood, MS.

Two of GE's Tier 4 demonstrators lead a Pasco, WA to Barstow, CA manifest, as it approaches tunnel #2 in the Tehachapi Mountains.

Pasco to Northtown freight H-PASNTW with GE Demo 2033 in the lead prepare to depart Pasco. Photo taken with permission with full PPE.

3 GE Tier 4's lead a eastbound HPASNTW at Cut bank, MT.

3 GE demos lead a westbound Northtown to Pasco freight just east of Browning, Montana.

GECX Tier 4 demos currently testing on BNSF's Northern Transcon. Pasco, WA. Photo taken with permission with full PPE.

With their work completed at Mattoon Yard, A431 departs on the final leg of its journey from Memphis, Tenn., to Decatur, Ill. A pair of Tier 4 GE demonstrator units lead on May 22, 2015.

Up close and personal with the GE Tier 4 demonstrator as it sits in the service area at CSX Selkirk Yard.

Freshly released from the shop for an EGR modification, two of GE's Tier 4 demonstrator ES44AC's scream downhill into Berthold at 70MPH with a measly 1,455 feet of super-hot UPS traffic.

Two tier 4 demonstrators sit on the servicing tracks in Willmar after bringing a train in off of the Morris Sub earlier in the day.

One of only 4 so far. This ES44A6 has Twin Turbo and new EGR system to meet the latest EPA Tier 4 emissions rating.