Octane
gas prices 9/29/2005
gas prices 1/29/2006
gas prices 12/21/2006
| US | Germany | RON | MON | (RON+MON)/2 | ||||
| Regular | 87 | Normal/bleifrei | 91 | 91 | 82.5 | 86.75 | ||
| Plus | 89 | Euro Super | 95 | 95 | 85 | 90 | ||
| Premium | 91 to 94 | Super Plus | 98 | 98 | 88 | 93 |
MLs require premium unleaded fuel with 95 RON/85 MON according to the international (ROW) manual. Temporarily they can be run with 91 RON/82.5 MON while avoiding full throttle.
US MLs require "91 pump octane" according to the US manual but run fine with a few tankfulls of lower grades as well, maybe reducing power somewhat.
US pumps show the average of the RON (research octane number) and MON (motor octane number) whereas pumps in Germany and e.g. China only show the higher RON.
In the mountains lower octane fuel can be used. At 6000 feet the air pressure drops to 80% of sealevel thus reducing the effective ML compression ratio from 10:1 to 8:1 which prevents acceleration pinging.
The new sulfur free (under 10 ppm) Shell Optimax became available during the summer 2000 in Germany and is designed for the new direct injection gasoline engines. The Ferrari F1 team uses Shell products and even showed a race car driving with Optimax from a standard station.
Gasoline should conform with ASTM D4814, Standard Specification for Automotive Spark-Ignition Engine Fuel, Euro Super. In Europe gas must conform to EN228, permitting a maximum of 150 ppm sulfur since January 1, 2000.
Maximum sulfur content in USA gas ================================= Conventional gasoline 1000 ppm Reformulated gasoline 500 ppm California since 1996 80 ppm California since 2004 60 ppm California starting 2006 30 ppm
Alliance calls for improved fuel quality worldwide
PARIS, Sept 27 2003 (Reuters) An unprecedented alliance of 13 automakers called for international harmonisation of vehicle regulations, worldwide acceptance of clean diesel technology, the promotion of advanced technology and for improved fuel quality worldwide.
Chevron, QuikTrip, Conoco, Phillips, 76, Shell meet new "TOP TIER Detergent Gasoline" Spec
Chevron press release
QuikTrip press release
www.toptier.com
6/14/2004
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Veni, vidi, M. |