Ground clearance
In vehicles, the ground clearance refers to the distance to the ground, in cars it is generally the distance between the lowest point of the body and the road . In some cases it makes sense to indicate where the measurements were taken on the vehicle. The term is also used for other vehicles (e.g. tanks , amphibious vehicles , tractors ).
In off-road vehicles , the ground clearance under the axles and the ground clearance between the axles are generally of interest. There is the following definition:
"The ground clearance under an axle is determined by the vertex of an arc that goes through the center of the contact area of the tires on one axle and touches the lowest fixed point of the vehicle between the wheels."
The ground clearance between the axles is colloquially referred to as abdominal clearance and is closely related to the ramp angle . Definition from Directive 92/53 / EEC :
"The ground clearance between the axles is the smallest distance between the ground level and the lowest fixed point on the vehicle."
With lowered vehicles, the low ground clearance can lead to restrictions in everyday use because natural or artificial obstacles ( speed bumps ) can often no longer be driven over without damage.
Minimum ground clearance
In Germany there is no legally binding minimum floor clearance. However, the provisions of Section 30 (1) and (2) StVZO justify a general restriction on the permissible ground clearance.
"(1) Vehicles must be built and equipped in such a way that
- 1. their normal business activities do not harm anyone or endanger, hinder or annoy anyone more than is unavoidable,
- 2. [...]
(2) Vehicles must be built in a road-friendly manner and be maintained in this way. "
During the general inspection of motor vehicles, the inspector will primarily orient himself on the recommendation “VdTÜV Merkblatt 751”. In its Annex II, Paragraph 5.1.9, it says:
"Lowered vehicles, occupied by a driver, full fuel tanks, must be able to drive over an obstacle 800 mm wide and 110 mm high in the center without contact."
Ultimately, it is up to the tester how little ground clearance he allows, but the TÜV recommendation has become the rule when assessing a vehicle situation.
In Austria, decree 190500/8-II / B / 5/00 of the Federal Ministry for Transport, Innovation and Technology of August 3, 2000 was in effect until mid-2015 . With the new decree of June 22, 2015, the VdTÜV leaflet 751 from 2008 regarded as state of the art. Among other things, residual spring travel and limit spring rates were redefined as an alternative to the previously required minimum ground clearance of 110 mm.
Minimum clearances
Regardless of the ground clearance of the vehicle floor, there are minimum clearances to the road surface for a number of add-on parts. In Germany - usually in the StVZO - the following restrictions are binding:
| • High and low beam | 500 mm | Section 50 (1) StVZO |
| • Side indicators | 500 mm | § 54 StVZO |
| • Fog lights | 250 mm | § 52 StVZO |
| • Brake light | 350 mm | § 53 Abs. 1 StVZO |
| • Front license plate | 200 mm | Section 10 (7) FZV |
| • Tail light | 350 mm | § 53 Abs. 1 StVZO |
| • Rear license plate | 300 mm | Directive 70/222 / EEC |
| • Rear fog light | 250 mm | Section 52a Paragraph 1, Section 53d StVZO |
| • Front indicators | 350 mm | § 54 StVZO |
| • Reversing lights | 250 mm | § 53a Abs. 3 StVZO |
| • Rear turn signals | 350 mm | § 54 StVZO |
| • Side marker lights | 250 mm | Section 51 Paragraph 3, Section 51a StVZO |
Many of these paragraphs have been adapted and correspond to the UN / ECE directive ECE-R 48 on uniform conditions for the approval of vehicles with regard to the installation of lighting and light signaling devices .