Amid the evolving diesel emissions scandal involving Volkswagen’s TDI models, many analysts are watching the situation closely for any dramatic shifts in these models' residuals and sales.

In other words, what impact will the alleged “defeat device” software and the resulting firestorm from regulators and the EPA have on consumer and dealer interest in the models.

Auto Remarketing reported Monday that dealers in the lanes are already being much more cautious about purchasing certain VW models.

And Kelley Blue Book analyst Tim Fleming said, “Early indications from auctions are that dealers are more hesitant to buy the VW diesel units, with sale prices falling 13 percent in the two weeks following VW’s announcement, compared to a 2-percent drop for the comparable gas-powered models.”

Black Book editors offered their take on the situation in the latest weekly Black Book Market Insights report, showing wholesale value trends on VW diesel models impacted by the EPA notification versus competitive gas models in the same segments.

The results were telling, with each model studied showing higher depreciation than their gas counterparts.

For example, prices for the Jetta Diesel have dropped by 7.9 percent since the news broke in late September. From that same Sept. 18 date, competitive gas models have seen prices drop by only 3.5 percent.

The Beetle Diesel is suffering, as well. The model has depreciated by 6.5 percent since the end of September, while competitive gas models have only dropped by 2.3 percent during the same period.

Lastly, the Passat Diesel saw similar drops, with a depreciation rate of 7.9 percent. On the other hand competitive gas models for this unit only fell by 2.3 percent since Sept. 18.

Auction sales suffering for VW TDI models

NADA Used Car Guide analysts also offers a VW emissions scandal update in the latest Guidelines Report, which stated damage to VW’s used-vehicle prices — both for affected diesel engine models and gas powered models not impacted by the scandal.

“Unfortunately the relatively small number of VW diesels passing through the used market combined with uncertainty surrounding VW’s plan to bring affected vehicles into compliance make it difficult to pinpoint how disruptive the issue has been to the used VW market thus far,” writes Jonathan Banks, senior director of vehicle analysis and analytics at NADA UCG and speaker at the upcoming Used Car Week Conferences. “To-date, there is some indication that VW auction sales activity has been affected, however, any impact to VW prices remains inconclusive.”

Take this for example: VW auctions sales for model years 2009-2015 fell by an average of 7 percent over the two-week period ending Oct. 3, when compared to levels averaged in the four weeks prior, according to the Guidelines report.

“While well above the 1 percent drop recorded for the industry as a whole, VW’s decline was matched or exceeded by a handful of brands including GMC, Infiniti, Mercedes and Subaru,” Banks added.

When looking strictly at changes for VW diesel models, the drops were more pronounced.

Sales of VW Beetle, Golf, and Jetta diesel models were off by 28 percent, Banks reported, while sales of gas models were flat. Sales of Passat diesel and gas variants were down 33 percent and 18 percent, respectively.

Auction volume of VW’s compact cars in the lanes, including both gas and diesel variants, is also waning. Volume fell by an average of 4 percent over the aforementioned two-week period.

That said, VW wasn’t the only brand to experience a drop in compact car value, as Mazda saw a 2-percent decline and Toyota experienced a 3-percent volume drop in this segment.

“In terms of pricing, a careful review of used retail and wholesale price movement has yet to reveal any consistent change in the trajectory of VW prices — diesel or otherwise — compared to the competition,” Banks said in the report. “Additional time will have to pass before we can draw more definitive conclusions on the issue.”

If interested in further coverage on the Volkswagen TDI issues, see the recent Auto Remarketing features below:

VW inquiries up 10% at KBB, 7% at Autotrader

VW diesel issue impact on CPO & prices

How VW gas & diesel prices are faring at auction

VW’s diesel refit plan draws questions