Agriculture 2023, 13, 87. https://doi.org/10.3390/agriculture13010087 www.mdpi.com/journal/agriculture Article Assessment of the Performance of Agricultural Tires Using a Mobile Test Bench Roberto Fanigliulo, Marcello Biocca *, Renato Grilli, Laura Fornaciari, Pietro Gallo, Stefano Benigni, Paolo Mattei and Daniele Pochi Consiglio per la Ricerca in Agricoltura e l’Analisi dell’Economia Agraria (CREA), Centro di Ricerca Ingegneria e Trasformazioni Agroalimentari, Via della Pascolare 16, Monterotondo, 00015 Rome, Italy * Correspondence: marcello.biocca@crea.gov.it; Tel.: +39‐06‐90675215 Abstract: The performance of agricultural tires varies with the characteristics of both the terrain and the tractors on which they are mounted, which differently affect the rolling resistance, the traction capacity, and the slip. To reduce the variability of test conditions, CREA developed an original mobile test (MTB) bench which consists of a dynamometric single axle trailer pulled by a tractor and can be used both in traction performance tests (driving wheels) and in rolling resistance tests (driven wheels). A control system alternatively operates the adjustment of traction force or slip, so that each test is performed maintaining constant the desired values. The MTB underwent tests under different conditions (type of surface, pre‐set values of force of traction and slip) aimed at verifying its accuracy and reliability. In a final test, two pairs of identical new tires were simultaneously mounted on the MTB and on the rear axle of the 2WD tractor that pulled it, to discover information on the different interactions occurring, under the same traction conditions, between the soil surface and each pair of tires, with reference to the relationship between the slips and the load transfers observed on the MTB and on the tractor rear axle. The results evidenced the capability of the MTB to guarantee repeatable test conditions, including field conditions, allowing comparison among the performance of different tires. Keywords: tires tests; tractive performance; slip; dynamic load; rolling resistance; brake test; measurement sensors 1. Introduction The study of the performance of agricultural tires particularly involves the properties of traction performance, slip, rolling resistance and the effects on soil compaction. Furthermore, aspects of safety and comfort have become important in recent years, considering the increasing speed limits allowed for tractors during transport on roads. The characteristics of agricultural tires and the instructions for their use and storage are annually published by the European Tire and Rim Technical Organization [1] and by ISO 11795:2018 [2]. Agricultural tractors are normally employed as power sources for pulling farm implements, through the conversion of engine power in useful drawbar power, thanks to the action of different typology tires with relative specific configurations (such as inflation pressure and wheel load), able to discharge the traction power on the ground. The tests on agricultural tires are commonly carried out at fixed points, using devices capable of adjusting the load conditions and simulating the contact with the tractive surface, or mounting the tires on vehicles they are designed for. In the first case, the tire testing conditions are often different from the real operational conditions; in the second case, the results of the tests are strongly affected by the interaction of factors not directly connected with the tires to test. The problem is further complicated by the variability of tire behaviour on various soil surface conditions. Consequently, the test conditions are Citation: Fanigliulo, R.; Biocca, M.; Grilli, R.; Fornaciari, L.; Gallo, P.; Benigni, S.; Mattei, P.; Pochi, D. Assessment of the Performance of Agricultural Tires Using a Mobile Test Bench. Agriculture 2023, 13, 87. https://doi.org/ 10.3390/agriculture13010087 Academic Editor: Kenshi Sakai Received: 6 December 2022 Revised: 23 December 2022 Accepted: 26 December 2022 Published: 28 December 2022 Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/license s/by/4.0/).