The Continental Grand Prix 4 Season is a top of the line, all-season road bike tire. This tire is a close cousin of the Grand Prix 4000S II. Both tires use a 3/330 TPI carcass and are handmade in Germany. To make the 4 Season an all-season tire, Continental designed this tire with a double layer of Vectran breaker under the tread, an extra layer of DuraSkin from bead to bead, and a silica compound which is optimized for cold and wet weather.
When going for a tire like the Grand Prix 4 Season, rolling resistance is probably not the most important point to consider. Puncture resistance and grip on wet and cold surfaces will probably be the main selling point. I do think it's interesting to know the rolling resistance of the 4 Season, especially at lower air pressures. Being able to compare this with the GP4000S II data might make the decision to switch between summer/winter tires a bit easier.
Most Continental high-end tires use the Continental Black Chili compound which always performs excellently in the rolling resistance tests. Surprisingly, the 4 Season doesn't use the Black Chili compound but instead uses a different "Max Grip" silica compound. This is a softer silica compound which can be used in all weather conditions. This will probably make the biggest difference during the rolling resistance test
|Model||Grand Prix 4 Season|
|Supplied By||Bought in store|
|New or Used||New|
|Compound||Max Grip Silica|
|Specified Weight||240 grams|
Size and Weight Measurements
|Size and Weight Measurements (Bike Wheel: 622x17C, Pressure: 100 psi / 6.9 bar)|
|Measured Weight||215 grams|
|Measured Width||27 mm|
|Measured Height||24 mm|
|Total Tire Thickness Center||2.7 mm|
|Total Tire Thickness Sidewall||0.7 mm|
While the specified weight of the 700 x 25C 4 Season is 240 grams, the tire used for this test weighted in at a very low 215 grams. This is even lower than the specified weight of the GP4000S II. With a weight this low, I wonder if there is enough rubber on this tire to make it last long enough. Measured width and height on a 17C rim is 27 mm and 24 mm respectively.
Rolling Resistance Test Results
|Rolling Resistance Test Results (Speed: 29 kmh / 18 mph, Load: 42.5 kg)|
|Rolling Resistance 120 psi / 8.3 Bar||17.2 Watts|
|Rolling Resistance 100 PSI / 6.9 Bar||18.1 Watts|
|Rolling Resistance 80 PSI / 5.5 Bar||19.8 Watts|
|Rolling Resistance 60 PSI / 4.1 Bar||22.5 Watts|
|Rolling Resistance Coefficient (Crr) 120 psi / 8.3 Bar||0.00516|
|Rolling Resistance Coefficient (Crr) 100 psi / 6.9 Bar||0.00543|
|Rolling Resistance Coefficient (Crr) 80 psi / 5.5 Bar||0.00594|
|Rolling Resistance Coefficient (Crr) 60 psi / 4.1 Bar||0.00674|
Rolling resistance is decent for an all-weather tire. At an air pressure of 120 psi, rolling resistance is 17.2 watts, which is 5 watts more than the GP4000S II. Dropping air pressure to 100 psi results in a rolling resistance of 18.2 watts (GP4000S = 12.9). At a more usable air pressure of 80 psi, rolling resistance is 19.8 watts, this is 6.1 watts more than the GP4000S II.
It's obvious rolling resistance isn't as low as most other summer tires. The differences also get bigger when dropping the air pressure to a more usable air pressure range (80 - 100 psi). Don't forget to look at the puncture resistance test results to make the comparison more complete.
Puncture Resistance Test Results
|Puncture Resistance Test Results (higher is better)|
|Puncture Resistance Tread||17|
|Puncture Resistance Sidewall||7|
One of the main selling points of the 4 Season is its claimed high puncture resistance. With a score of 17 points in the puncture resistance test, the 4 Season performs excellently. 17 points is much higher than the 11 points the GP4000S scored.
A more comparable tire is the Continental Gatorskin which scored 18 points in the puncture resistance test. The Gatorskin does have an even higher rolling resistance of 19.3 watts at 120 psi.
As expected, rolling resistance is a bit higher than pure summer tires like the GP4000S II or Schwalbe One. For a pair of tires, cycling at a speed of 18 mph / 29 km/h, an extra 10 to 12 watts of power input is required to obtain the same speed. In return for this extra effort, you get a much stronger tire and increased grip in cold and wet conditions. When taking both into consideration, the Grand Prix 4 Season is a great tire.
I would have given the Grand Prix 4 Season a 5-star rating if it would have had just a little lower rolling resistance. I was hoping it to come in closer to the 16 watts range. Still, it is a great tire with a high puncture resistance and low rolling resistance. I'm interested in your opinion about it's wet and cold weather qualities as well. Let me know in the comments.
RATING: 4 / 5
TEST VERDICT: Recommended
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