1995 BMW 325i

Yesterday we tested a 1995 BMW 325i equipped with a 2.5L L6 engine. This is a popular car from BMW and the 2.5L has been widely used.

Stock Bosch Super Plus FR7LDC plugs installed the engine made 190 Peak HP at 6000 rpm and 182 Peak Ft-Lbs of torque at 4400 rpm. 40 to 80 mph acceleration took 9.45 seconds and the 8.2 mile fuel economy trace took 1173.5 cc to complete.

Pulstar BE-1 plugs installed the engine output climbed to 197 hp at 6000 rpm and 184 Ft-Lbs at 4400 rpm. Acceleration times dropped to 9.39 seconds and the same 8.2 fuel economy trace took only 1080.7 cc to complete.

So, for the results, we gained 7 HP (3.7%) and 2 Ft-Lbs (1.1%) of torque and reduced fuel consumption by 92.7 cc (7.9%). Lets take a look at fuel costs, this car averages about 30MPG overall. That's around 500 gallons a year (assuming 15k miles driven) and at $3.50 a gallon that's $1750 in gas alone to drive the car for a year. If we were to reduce that by 7.9% we save $138.25, almost the entire $163.15 cost of the plugs in the first year. Over the rated life of the plugs you would save $460.37 in fuel costs.

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2004 BMW Z4

On Febuary 1st, 2008 a 2004 BMW Z4 got strapped to the rollers in our lab for testing.

The stock plugs on this car have been the talk of the auto industry for some time now. The stock plugs in this BMW are the Bosch R3 or Platinum +4 plugs. The idea behind them is that 4 points of possible ignition will give you a much more reliable spark and the surface-gap discharge design should give you the most combustion chamber exposure.

With new stock plugs we run our first set of testing again. We got a 40mph to 80mph acceleration of 9.24 seconds over a distance of 0.16 miles. Peak horsepower was 211 at 6000rpm and torque peaked at 193 Ft-Lb at 4000rpm. Fuel consumption over the fuel economy test was 1174.99cc.

With new Pulstar BE-1 plugs we attained a 40-80 mph acceleration of 9.07 seconds over 0.15 miles. We made 218 horsepower at 6000rpm and 202 Ft-Lb at 4000rpm. Finally, our fuel consumption trace took 1100.34cc.

We did fairly well with this car; gained 7 horsepower (3.3%) and 9 pounds of torque (4.7%). We reduced passing acceleration by 0.17 seconds (1.7%) and fuel consumption by 74.95cc (6.4%).

In the market of performance modifications we fair well among the other options out there for Z4 owners. We cost $23.31 per hp gain. A CAI for this vehicle runs around $350 and typically gives the Z4 about 11hp making it a $31.82 per hp upgrade, again, remember that this is a wide open throttle figure and part throttle gains aren't to be had with a cold air intake. An exhaust system will run you about $750 and that's around $50.00 per hp assuming it gives you 15 hp(a reasonable number).

www.pulstar.com