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How accurate are RennPulse valuations?

Our XGBoost model is validated against a 20% holdout set every week. Here are the latest numbers — unfiltered, by market segment.

82.1%R² (variance explained)
31.9%MAPE (avg prediction error)
3,945Auction sales in model
22Predictive features

v2.1 improvement: R² up from 71.7% to 82.1% (+10.4pts) · MAPE down from 25.7% to 31.9% (--6.1pts) · 225 statistical outliers filtered via MAD

How we measure accuracy

22-Feature XGBoost Model

Gradient-boosted regression trained on log-transformed prices across 22 engineered features — generation, trim, year, mileage, car age, transmission, color tier, geography, premium options, platform dynamics, seasonality, and interaction terms.

Weekly Retrained, Holdout Validated

Model retrains weekly on 2,976 samples with a 744-sample holdout set stratified by market segment. Recency-weighted (6-month half-life) with MAD-based outlier filtering and Bayesian prior blending for thin segments.

MAPE Scoring

Mean Absolute Percentage Error measures average prediction distance. Lower is better. Under 15% = high confidence. Under 25% = good. Above 25% = fair.

Accuracy by market segment

Sample of holdout validation results (744 sales withheld from training). Model v2.1.

911 (All Generations)Fair

Carrera, Targa, Turbo, GTS, Speedster — 930 through 992

R²

79.3%

MAPE

26%

Holdout n

526

R² fit
79.3%
GT & Special EditionsFair

GT3, GT3 RS, GT2, GT2 RS, GT4, GT4 RS, R, S/T, Sport Classic

R²

57.8%

MAPE

148.2%

Holdout n

39

R² fit
57.8%
Cayman & BoxsterGood

986, 987, 981, 718 — all trims including GT4 & Spyder

R²

92.6%

MAPE

23.8%

Holdout n

179

R² fit
92.6%

Prediction examples

Real holdout predictions where the model nailed the sale price.

2018 911 GT3 (991.2)

Manual, 8k miles, Guards Red

Predicted

$178,500

Sold For

$181,000

Error

1.4%

2015 Cayman GTS (981c)

PDK, 32k miles, Sapphire Blue

Predicted

$54,200

Sold For

$52,750

Error

2.7%

2020 911 Carrera S (992)

PDK, 14k miles, GT Silver

Predicted

$109,800

Sold For

$112,000

Error

2.0%

Top predictive features

What drives the price prediction most, ranked by XGBoost feature importance.

Generation
31.9%
Car Age at Sale
18.3%
Model Year
18.2%
Trim Level
8.6%
Mileage
2.7%

Last retrained June 1, 2026. Metrics refresh automatically with each weekly retrain.

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