GR8NSTAR Posted August 10, 2004 Report Share Posted August 10, 2004 Hello all. Myself, wife, and Bernadette(98 deville) decided that we'd take us a lil roadtrip this past weekend (Aug 6th-9th) to visit some old friends of ours in Overland Park, KS (a kansas City suburb). I figured this would be a good outing for Bernandette to stretch her legs. I must tell ya that Bernadette and her heart (engine) makes traveling on road trips very inexpensive considering the gas prices. We live in Colorado Springs, CO. I topped off at a shell station prior to leaving home with premium unleaded fuel and reset my trip counter and gallons used 0. The ride was as smooth as silk. I traveled on HWY 24 east where the avg speed was 65 mph to I-70 east(Limon, CO) where the speed limit is 75mph all the to our friends front door on that same tank of gas . When we arrived my fuel light was flashing the E symbol as Bernadette reminded me that she was very thirsty. I had totally forgotten about putting gas in her along the way. When I had thought about it we had just passed through Topeka, KS. I woke my wife up to look at the map to see how much farther we had to travel because fuel was definitely a need. To my surprise she said baby according to the map we were about 45 miles from our destination. I looked to see what was my remaining distance on the range info and it showed 70 miles. So I just leaned my seat back a lil and cruised right on in . 596 miles was how far we had traveled from Colo. Spgs. at $40 for a tank of gas.....unbelievable. I'm definitely a caddy man for life and this one is my very first too. I must mention to some skeptics that we left town about 8pm Thurs night wich afforded me the luxury of not having to run the ac and my cruise control was always locked in about 1-2 mph over the posted speed limit. I did however come across a candy apple red sedan deville late 90's model that played follow the leader with me for about 40 miles. If you're out there just wanted to say thanks....you helped me stay awake during that time frame. CADDY 4 LIFE Link to comment Share on other sites More sharing options...
JasonA Posted August 10, 2004 Report Share Posted August 10, 2004 Yeah man. 600 miles on 20 gallons is just about 30 mpg. Gotta love the LD8/3.11 combination! I average between 28-30 mpg on road trips, and nobody believes it. They think even new Cadillacs are gas guzzlers. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
GR8NSTAR Posted August 10, 2004 Author Report Share Posted August 10, 2004 Jadcock so you know all too well of my battle with people believing me about going 600 miles on a tank of gas. I mean they'll say something like man, darn that's good, but they say it with that wink...wink tone....like yeah, right. I wish I could take a non believer one day and we start out on that same road trip together so they can see for themselves. Maybe they'll buy a caddy too . A friend of mine told me that the reason gas mileage is so great is because the N* is 8 cylinders/32 valves and what happens is when you're at a cruising speed like that, 16 of those valves actually shut down running the car on 4 cylinders so gas is saved. He went on to say that the very moment that you hit the gas pedal the other 16 valves kick right back in bringing you back up to 8 cylinders again, and that's the immediate thrust you feel when you hit the accelerator. I'm not sure if what he say's is true but I'll never complain when I can get those type of miles on a tank of gas. Does anyone out there know if there's any truth to my friends explaination? BTW he owns a 96 sedan deville. Link to comment Share on other sites More sharing options...
Vince P Posted August 10, 2004 Report Share Posted August 10, 2004 Mileage Let me add: I have a 1994 SLS, with 150,000 miles. I consistantly get --------------30mpg----on long trips. Vince P Link to comment Share on other sites More sharing options...
JasonA Posted August 10, 2004 Report Share Posted August 10, 2004 A friend of mine told me that the reason gas mileage is so great is because the N* is 8 cylinders/32 valves and what happens is when you're at a cruising speed like that, 16 of those valves actually shut down running the car on 4 cylinders so gas is saved. No, that's not true, but I like his explanation! The Northstar is a 32 valve V-8 engine, but that's the only part he got right. The rear wheel drive Northstars (new XLR, SRX, STS) have variable valve timing, but nothing that shuts certain valves off. They had that way back in the early '80s on a big V-8, but not on the Northstar. He's mistaken about the function, but not about the result. It's a relatively small displacement V-8 that, under cruise, can generate really great mileage numbers. The 3.11 transaxle REALLY benefits the mileage, because you're turning the engine so much slower. This is what you have in your Deville (and what your buddy has in his), and what all the SLSes have and regular Eldorados. We can drive 75 mph and still not be turning 2000 rpm engine speed. An STS (with the 3.71 transaxle) would be close to 2500 rpm probably at that speed...and they get worse mileage. The performance/mileage tradeoff is clear as night and day in this case. The main difference between the two powertrain packages is the transaxle ratio. THe LD8 engine has 275 hp and 300 lb*ft of torque. The L37 engine has 300 hp and 295 lb*ft of torque, both at higher peaks than the LD8 engine. The L37 is paired with the 3.71 transaxle to help overcome the loss of torque. The differences in the engines are very slight, but the difference in transaxle ratios accounts for the big difference in mileage, as far as I can tell. Most of the STS folks get anywhere from 22 to 26 on the road, according to general reports here. Most of the SLS folks get between 28 and 30. Even relatively "low-tech" engines can get good mileage under the right circumstances. The big 6.0-liter LS2 V-8 (an OHV engine of 16 valves) in the new C6 Corvette is rated at 19 mpg city and 28 mpg highway. Woah! That's a better EPA rating than our Northstar Cadillacs! Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
GR8NSTAR Posted August 10, 2004 Author Report Share Posted August 10, 2004 Vince P so you're at a 150,000 miles and still running strong. I'm at 79k now so I still have a lot of happy driving to look fwd too.......barring a catastrophe like getting the car totaled Link to comment Share on other sites More sharing options...
GR8NSTAR Posted August 10, 2004 Author Report Share Posted August 10, 2004 JADCOCK, Thanx for the explanation. I'll be sure to explain this to him as well so he'll be more informed. You mentioned the you last post that the rear wheel drive Northstars (new XLR, SRX, STS) have variable valve timing. My 98 deville is front will drive. Would your explanation also hold true for front wheel drive N*s? Link to comment Share on other sites More sharing options...
JasonA Posted August 10, 2004 Report Share Posted August 10, 2004 You mentioned the you last post that the rear wheel drive Northstars (new XLR, SRX, STS) have variable valve timing. My 98 deville is front will drive. Would your explanation also hold true for front wheel drive N*s? I don't think so -- and certainly nothing before 2004 has VVT. I don't think they're putting that on the FWD engines right now. The VVT Northstars are rated at 320 hp and 315 lb*ft of torque I think...or numbers really close to that. The engines are pretty much the same from 1993 through 1999, inclusive. For the 2000 model year, the engine was substantially redesigned and was optimized for regular fuel, even though many people also use regular in a 93-99 car. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
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