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[Shotimes] My MPG Test is Working!!

To: shotimes@autox.team.net, <shotimes@autox.team.net>(SHOTimes)
Subject: [Shotimes] My MPG Test is Working!!
From: krazgeo@comcast.net
Date: Tue, 08 Aug 2006 06:16:37 +0000
"We're on the road now.....

Speaking of which.....Yay!!  It works!!  (The idea of larger tires to get 
economy.)

We're on a week's trip to NE California and Crater Lake.  The first day took 
the GS from home to South Lake Tahoe via Hwy 50, which is two lane much of the 
way up the hill to Echo Summit, which is about 7000 feet or so.  We stopped at 
a Costco just at the base of the hill to refuel....might as well since the gas 
is cheapest there.  From there to the lake, climbing the hill and driving at 
the limit with intelligence,  it got 22 mpg, with three folks and about 75 lbs 
of luggage.  That was about the same as the BMW gets....nice, but no big deal.  

(The AAA "How does this car rate" website says their '98-'05 (one of those) GS 
300 got about 17 mpg in mixed driving....I KNOW I can beat that, without doing 
anything to the car.  I'm pretty sure this one was rated at 17 city, and 23 
highway.)  

So, anyway....the next leg was the test...today's trip from Tahoe through Reno 
and Susanville up 395 and 299/139 to Klamath Falls and 140 to Medford.  That 
was 401.1 miles (7.5 hours of driving) from the Costco in Carson City to the 
one in Medford.  I kept the speed at the speed limit....it was 70 in Nevada, 65 
in Ca., and 55 in Oregon.  We did have to stop three times for road 
construction...waiting in line for the pilot car to lead the oncoming traffic 
through a one-lane stretch (I shut it down each time), plus the obligatory 
tinkle stops, and we also had to drive through the downtown sections of Carson 
City, and also Klamath Falls.  The K Falls stretch was about 15 miles, and took 
the overall average down by a mpg or so, I'm sure.  I was watching the gas 
gauge 'not' fall down fast today like it used to do, and was looking for a good 
number.  I got it.

It got (as best as I can figure with the numbers I have....) 30.6159 mpg, using 
13.101 gallons to go that distance.  Altitude had some input, too...the average 
altitude for this leg was over 4,000 feet.  We'll check what it gets below 500 
MSL on the way home down I-5 on Friday.  

I think the engine is at the ideal rev range now, at 2500 +/- 50 at 65 mph.  
Climbing up a steady gentle slope in Oregon at 55, where the revs were down to 
about 2150, the car could not maintain speed in 5th gear without complaining.  
The cruise would instantly shift to 4th gear.  If I held it with my foot, it 
would decrease speed very (!) slowly, until the torque converter would unlock, 
allowing the revs to go up to 2400.  Then the car could accelerate...very 
slowly...but accelerate, at that road speed.  That tells me the torque is a bit 
low below 22-2300 RPM.  2500 looks like a good all around engine target speed.  
(I was thinking of trying to gear it down to 2100 at 65...probably too slow.)

Now, if I apply the same logic to the SHO, and modify the front strut spring 
seats to allow 1 inch larger tires for cruising, I should be able to get 35 mpg 
at 70 mph at sea level.  That'll be fun to try!!   ;-)   It's got LOTS of 
torque, right?

George
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