Buick and Lexus ranked highest in overall vehicle dependability, which improved 9% overall in the past year, according to J.D. Power's annual Vehicle Dependability Study.

The study measures the number of problems per 100 vehicles (PP100) experienced during the past 12 months by original owners of 2015 model year vehicles. The overall industry average improved to 142 PP100. The improvement is the first since the 2013 study, which is now in its 29th year.

Commercial fleets using a three-year lifecycle approach to replacement units could be positioned to take advantage of higher resale values of 2015 vehicles, fleet management company experts said.

"With observed vehicle dependability rising to the highest levels in the last five years, some fleet managers may be more inclined to extend vehicle replacement cycles, while others may take advantage of anticipated sales increases in the used vehicle market," said George Albright, assistant director of fleet maintenance for Merchants Fleet Management. "In either case, fleet managers should leverage this report as an additional tool when evaluating their choices, especially if considering replacement options between multiple manufacturers."

In the study, Lexus ranked highest in the study with 99 PP100, while Porsche was second with 100 PP100. Among mass market brands, Buick led the way with a score of 116 PP100.

Fiat is the most improved brand with owners reporting 106 fewer PP100 than in 2017. Infiniti has also seen major improvement by moving to fourth place from 29th a year ago. Other brands with strong improvement, include Nissan (37 PP100 fewer) and Ford (31 PP100 fewer). Kia, Dodge, and Nissan recorded their best-ever rankings.

The study also names the top vehicle among eight car categories and 11 SUV, van and pickup segments. Toyota vehicles including the Prius and Tacoma topped six of the segments. General Motors won five segment awards for the Chevrolet Silverado, Equinox, Malibu, Traverse, and Buick LaCrosse. Ford earned segment awards for its Expedition and Super Duty trucks.

In-vehicle technology continues to cause the most problems with audio, communications, entertainment, and navigation bringing the most complaints. Voice recognition (9.3 PP100) and Bluetooth connectivity (7.7 PP100) ranked as the most common problems.

Other fleet experts urged fleet managers to stay on script with a lifecycle evaluation based on time and miles.

"Typically, fleet managers cycle based on original parameters, so even though dependability may have increased, they are still going to cycle using the same length of time/miles," said Dan Powers, Donlen's  remarketing director. "From a remarketing perspective, news of increased dependability will help when selling units in the market place."