old sub freak Posted February 15, 2004 Share Posted February 15, 2004 i installed a"mileometer" [vacume gage} on my ea81 hacth. its sposed to tell you when you get the best milage per vacume presure. well on the freeway at say 65mph in 3rd gear, 3500 rpms the guage reads GOOD/ high vacume. i shift to 4th,2000-2500rpms it reads POOR low vacume. i have 14 in tires so i'm some what guessing on the mph. i'm to lazy to really check the mpg{hey thats why i bought the mileometer} so i would think you would get better gas milage in 3rd/3500rpm. what are your thougts? and i'll sure try to do hood river. toddw/northern aliance crew ] Link to comment Share on other sites More sharing options...
Snowman Posted February 15, 2004 Share Posted February 15, 2004 I haven't done any scientific tests to prove this, but my soob sure seems a lot happier running between 3000 and 3500 than between 2000 and 2500. Below about 2800 rpm, it starts to fall off the torque curve and has to struggle, which is bad for fuel economy. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 15, 2004 Share Posted February 15, 2004 you have just discovered the reason we run the 81/82 4 speed D/R with big tires - or 4th gear of a 5 speed D/R. The gearing on the 81/82 is such that 4th is actually usable with my 28's..... GD Link to comment Share on other sites More sharing options...
ezapar Posted February 15, 2004 Share Posted February 15, 2004 Todd's brat is an 82. He "discovered" it about 10 years ago. Link to comment Share on other sites More sharing options...
myossfeece Posted February 15, 2004 Share Posted February 15, 2004 with my RX and the 16inch big wheels I seemed to get the best fuel econ between 3000 and 3500 rpm on the highway. Since then I have put the stock wheels back on for handling in the snow, even with stock tires it pulls better all around but seems to want to ride between 3200 and 3700 rpm. I seem to be getting about 26-29 mpg on the highway and somewhere around 21-24 in the city. So for best fuel economy I keep it between 3 and 4 thousand rpm, and that is right where the torque is, when you put the gas down it wants to pull rather than bog. This is of course with a carbbed block, turbo top end, 87 octane fuel, stock wheels, and stock full-time-4x4 d/r. I often wonder if lo-range would be better for fuel economy, because there would be less load on the engine, but it would be turning higher rpm to maintain the same speed, it is be more practical to use in the city where you don't get up to high speeds. However I have hit the highway in adverse conditions and maintained about 4500 rpm (75 mph) in lo range for extended periods of time and have had no trouble. You should get a little better economy than me if you have a part time 4x4 tranny, less gears to turn, less load, etc. Link to comment Share on other sites More sharing options...
old sub freak Posted February 16, 2004 Author Share Posted February 16, 2004 thanks for the imput. i'll run em tight, 3000-4000 rpm.i never liked luggin it. todd Link to comment Share on other sites More sharing options...
Meeky Moose Posted February 16, 2004 Share Posted February 16, 2004 well my ea81 hatch, all stock on the long trips i run at about 3500 rpms which is about 73 mph... gets 32mpg short trips to work it runs about 2000-2500 at 55-65.. gets about 26 mpg this way.. Link to comment Share on other sites More sharing options...
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