Speed made a huge difference with my 03 3500 srw. The difference between 65 and just under 75 was somewhere between 2 and 3 mpg.

The dually I have now will return 19 if you keep the speed down.

 

No need to speed here....I usually set my cruise 55-60, you don't save that much time anyway. Don't know why everybody has to be in such a hurry.

 

I use to run 5 over but have dropped down to the speed limit now with the higher fuel prices.

 

I have found my trucks "sweet spot" as far as RPM's and Fule economy is right at about 65mph... so unless I am ina big hurry, i drive 65........

 

I've found that my truck gets its best fuel mileage between 55 and 63 MPH. Like many here I too see a lot of people who drive 10-20 MPH over the speed limit. As long as the roads are not snow or ice covered I get passed by someone doing close to if not over 100 MPH at least once a month and in the summer once a week, so I guess the high price of gas does not affect everyone. I can say I've seen more semis going under the speed limit over the past 2 months so i can only guess the boss has told them to slow down.

 

Yeah, I guess the way I look at it, my MPG improves about 10-14%, which is like knocking 40 cents off the price of a gallon...

 

austin, thanks for mentioning your experiences with BMW. I can't afford to purchase one, but I am drawn to that make of automobile because of their inline six cylinder engines. The BMW's twin turbo 3.0 liter I-6 with 6 speed manual transmission really appeals to me. At the BMW dealership, I drove a 2007 twin turbo BMW 3 series and it was smooth as glass and powerfully strong in accelleration. The 5 series 2008 models appealed to me because they have somewhat more interior space than the 3 series.

What exactly was the problem with your 2004 5 series? Did it have the same engine that was in your 3 series? The 5 series is probably about four hundred pounds heavier than the 3 series. The new 535i seem like a super nice vehicle.

 

I drive by the tach, keep the rpms between 1500-1800 most of the time. Doing this I useually see about 16-17 around town and 21-22 on the highway. I have gotton 24 once had some tail wind and ran 1800 rpm the whole time, that is with my 285/75/17's

If I am in a hurry I might run 1900 on the highway, if I am pulling heavy I might go to 2300 before I let it shift the next gear but once rolling its around 1700-1800, some times I have to go slower and use 3rd gear on 45 mph roads.

I dont use od under 40 mph, I use 3rd with the tc locked up.

 

Just wait until their I-6 turbodiesels come over in a few months. You'll love them even more.

 

Its funny you posted this topic. On Saturday me and my GF were car shopping for her when I needed to fuel up. Well long story short, there were 2 PSD's fueling up and when I pulled out on the access road I dropped the hammer and got seriously sideways. My GF said what the hell did you do that for with diesel fuel so expensive, I looked her and said look at the 2 trucks at the pump now. She smiled and shrugged. I dont do that all the time but I figured they might like the straight pipe music.

 

I don't do that kind of stuff anymore, the way I see it I don't have to show off my truck and it's capabilities to another non-CTD filling up at the pump........It's a Cummins, we don't have to do those kinda things to show off and get attention, lol

 

I always drive about the limit and if Im on the freeway or I-94 I always keep it at 65-68 mph cause with the 4:10's and 285's that keeps my motor right at about 1950-1990 RPM's and my truck sees about 18-19 mpg SO I have changed nothing HAHAHA....Price still bites though As I dont get to hammer on it as much as I would like

 

Yup, I'm low-key as well.
Makes it easier to stay out of trouble, too.

 

Maybe around there... Around here everyone thinks Duramaxes (and even Powerstrokes) are the all time best.

 

The difference between them and us is they think they are the best but we KNOW we are the best!