Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site hou3c.UUCP Path: utzoo!watmath!clyde!burl!hou3c!rs From: rs@hou3c.UUCP (rs) Newsgroups: net.auto Subject: Re: "The biggest farce ever" faster speed =? better mpg Message-ID: <647@hou3c.UUCP> Date: Thu, 21-Jun-84 14:32:00 EDT Article-I.D.: hou3c.647 Posted: Thu Jun 21 14:32:00 1984 Date-Received: Fri, 22-Jun-84 07:47:16 EDT References: <2104@ihnss.UUCP> <714@ut-ngp.UUCP> <141@godot.UUCP> Organization: Bell Labs, Holmdel, NJ Lines: 24 It is worthy to note that the transmission is also important in determining what the optimum cruising speed is, for fuel ecomony purposes, as well as the other factors. In particular, manual transmission cars are sometimes equiped stock with innappropriate transmissions for highway cruising. For example, my brothers 1973 Datsan Z would get ~20 mpg at 70 mph and ~16 mpg at 60 mph primarily because of the 3rd and 4th gear ratios and the corresponding engine speed. (as well as the mandatory downshifts to get passing power at 60 mph). My 1968 Camaro had a 3 speed manual transmission that was geared such that the engine was turning about 3500 rpm at 55 mph. A lower ratio rear-end would have brought the rpms down for highway cruising, as well as give me more usable power in the lower gears (instead of just buring rubber when a fast start was attempted). A friend of mine did that with his 1978 Z-28 (350 ci. with a 4 barrel carb). His engine used to turn ~3600 rpm at 60 mph and now turns ~2400 rpm at 60 mph. On a recent long distance trip (to Canada) he got ~20-22 mpg on the highway. Bob Switzer AT&T Bell Labs ...!houxf!hou3c!rs