NHC MOTORS › Cases › GRANDEUR GN7
TYRE FITTING · ROAD FORCE · ALIGNMENT
New tyres on a Grandeur.
What about the small vibrations?
Sensitive to small changes in noise and vibration, this owner specifically requested Genesis OE tyres with acoustic foam. We fitted Continental tyres to match that request, optimised the tyre-and-wheel combinations to reduce RFV, then adjusted the four-wheel alignment.
Contents
01 / GRANDEUR GN7
Why the owner chose Genesis OE tyres with acoustic foam
This Grandeur GN7 owner notices small changes in driving feel and returns regularly for adjustment. Tyre noise also mattered, so the owner requested a Genesis original-equipment specification with internal acoustic foam. We fitted Continental tyres to meet that request.
New tyres vary between individual units. Their Road Force readings also depend on the wheels they are fitted to, so the assembled units need to be measured.
02 / GRANDEUR GN7
Why we removed tyres that were already fitted
Before the work, we checked RFV in the tyre-and-wheel assemblies and measured the alignment. Small vibrations cannot automatically be attributed to a tyre alone; we also considered its combination with the wheel.
On the Hunter Road Force machine, one assembly measured 10.0 kg, with a predicted matched value of 9.0 kg. Changing its mounting position on the same wheel offered limited improvement.
We removed fitted tyres and tried different wheel combinations. For a tyre with no inside/outside designation, we checked its mounting requirements and reversed its orientation before reassembling it.
The assembly identified by tag 4 measured 9.0 kg before the additional adjustment and 4.0 kg on remeasurement. It became the lowest of the four, and we revised the vehicle positions accordingly.
“We did not just want it within the limit; we wanted to get it as low as we could.”
Technician explaining the work · translated from Korean
Tag 4: additional matching
9.0 → 4.0 kg
Equipment-displayed RFV in kg. The earlier 10.0/9.0 kg current/predicted screen is a separate measurement stage.
03 / GRANDEUR GN7
Balancing left and right within the green range
Before adjustment, the toe readings were inside the equipment’s green range. However, front toe was 1.0/0.6 mm, rear toe was 0.4/1.5 mm, and thrust angle was −0.05°.
We set front toe to 0.7 mm on each side and rear toe to 1.2 mm on each side. Rear camber was set to −1.00° on both sides, with a thrust angle of 0.00°.
The owner’s familiar steering position and sensitivity to small changes mattered here. We considered left-to-right differences and the direction established by the rear wheels as well as the displayed tolerance range.
Four-wheel toe: before and after
Before
Front difference 0.4 mm · Rear 1.1 mm
After
Equal toe on each axle
Conceptual vehicle view. Wheel rotation is enlarged using the same scale for both panels; it is not an angle conversion from mm. All displayed toe values remain toe-in.
| Measurement | Before | After |
|---|---|---|
| Front left toe | 1.0 mm | 0.7 mm |
| Front right toe | 0.6 mm | 0.7 mm |
| Rear left toe | 0.4 mm | 1.2 mm |
| Rear right toe | 1.5 mm | 1.2 mm |
| Rear camber L / R | −0.98° / −0.82° | −1.00° / −1.00° |
| Thrust angle | −0.05° | 0.00° |
Original alignment measurements
04 / GRANDEUR GN7
Results: remeasured assemblies and adjusted alignment
The final RFV readings ranged from 4.0 to 7.0 kg. We remeasured the revised tyre-and-wheel combinations, chose their positions, then adjusted the alignment.
RFV and wheel alignment describe different things. RFV concerns force variation as a loaded assembly rotates; alignment concerns the direction and angles of the wheels.
After completing the work, we asked the owner for feedback from familiar driving conditions.
05 / GRANDEUR GN7
Care that follows how your car feels
Some drivers notice a small change in their own car before anything else. We ask when it occurs, what the road is like, and what feels different through the steering wheel or body, then consider those observations alongside the measurements.
This attention is not limited to imported performance cars. An everyday Grandeur can receive the same careful approach to tyre matching and wheel alignment.
Questions
Can a new tyre still benefit from Road Force measurement?
Yes. A new tyre does not guarantee a low RFV reading when assembled with a wheel. Here, reworking the combination reduced the same tagged assembly from 9.0 to 4.0 kg.
Why adjust alignment readings that are already green?
Green indicates the equipment’s selected tolerance range. This car still had left-to-right toe differences, which we adjusted while considering the owner’s steering position and driving feel.
Can any tyre be reversed on its wheel?
No. Mounting requirements depend on the tyre. In this case we checked the conditions of the tyre with no inside/outside designation before reversing it. Directional or asymmetric tyres must follow their specified mounting requirements.
Let us check what feels different
We check the tyre-and-wheel combinations and wheel alignment, taking your driving observations into account.
We explain the scope of any repairs and the estimate before proceeding with your approval.
Call 031-258-1617Book on NaverBy appointment only · Gwonseon-gu, Suwon
Total inspection scope and booking information (Korean)