Cool.......its all good then Chad.........here's hopin you get your way and a better experience all round.
Everyones got a different viewpoint which is just as well, otherwise there wouldn't be a forum

JC

 

No problems with the Mercedes? You were lucky!

 

Well, we will soon find out. I will be commuting in mine. I annually put on around 20-25k miles per year.[:@] I just hope that my X-type can hold up to the abuse. As far as mpg is concerned it isnt THAT bad. For a car its size with the awd its actually quite good. Its comparable to audi and mercedes as far as the awd mpg is concerned. HP is also very simular. With my 2.5L x-type it is rated at 19mpg city and 29hw. My car is equipped with a manual soi am sure i can squeeze a little more out of it. Also what kind of mercedes did you have? C-class, E-class? The 2001-06 C-class has excellent reviews for reliability. Plus the build quality is far superior to the jag but the jag is a bit more of a looker.

 

good luck trying to get 29hw milage, the best ive ever got is 24 and that was on a 2 hour trip with no traffic, and driving at the speed limit. i have a manual too, and it really doesnt make that much difference. Also it is no way near the mpg to that of an audi, audis give you way better milage, the A4 1.8 realistically gives about close to 30mpg. i dont think i wud ever be able to get that from the X[:@]

 

Well, thats what its rated at anyway...lol i am sure it was a bit inflated. I have a 2000 Seville STS that is supposedly rated at 27mpg hw and the best i have gotten was 23. Thats with 90%hw driving. Yes the 1.8 is better but the 3.0 if we are comparing class to class is simular in mileage. Atleast like i said on paper.

 

yeah, i agree with the comparison to the 3.0, my cousin has one of those (an 03) and he averages about 26mpg city driving, well thats what it says on the trip computer, but who knows if they are correct. The best mpg he got on the 3.0 was 33 mpg all highway milage

 

As 04 says Peewee.....good luck trying to get that sortax mileage.
I reckon at a push I can get 24-25 on highway runs.......Not good stop /start.

JC

 

Depends there folks...keep in mind highway is 55mph! When I roll out to my parents house that is between 45 minutes and an hour away (dependent on your speed) and I've gotten an average of 29.3 over the whole tank going out there. There and back I averaged around 28 for the whole trip...I was also accelerating very economically not to mention I was slowing down nicely and all of that good stuff....so its really dependent on you. When I drove to Wisconsin which was a few fill-ups I was averaging over 25 mpg and the computer said my average speed was 62...if you've ever played with your trip computer you know how hard it would be to get the average speed up to 62 when you are also getting off of the expressway...My true usual running speed coming home on the e-way was 85 but not lower than 80 as a running speed. The car in city driving is not good! My car is also an automatic and 3.0

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This is the thing though!
How many want to drive like that all the time?[&:] 55mph on the highway, accelerating very slowly, never braking unless you really have to, coasting down hills etc etc.
Don't get me wrong I've tried it for a day or so to see what economy I can get, but then, a short blast and bam, all your efforts have been in vain more or less.
If you got a fast car / supercar whatever, you wanna be able to drive it normally without worrying about mpg too much and give it a bit of a thrashing now n again, otherwise.....whats the point?

JC

 

My inline 6 gives me 15.2 mpg in the city of chicago, with an average speed of like 16. When I get lucky and there's no traffic on LSD, I can drive 45 miles per hour and get 27 miles per gallon. 45 is obtimum efficiecny I believe

 

No traffic on LSD.....lol.......sounds like you're on mind bending drugs 93
Over here, we've always considered 56 mph as the best speed for optimim fuel efficiency.

Jim

 

Best speed depends on the car. My XJS loved 70 to 80 MPH. My 91 Suburban 4x4 likes 50 to 55 MPH. At those speeds either vehicle gets well over (measured in tenths of a gallon per mile) 15 miles per gallon! Of course, just try to get the big ol' 4x4 to drive 70+!!!!! You had better have a statue of Mary on the dash -- you're gonna need it!

 

You're dead right Ken, My Audi seems to prefer 75-80.......but as a general rule across the board 56 is the recommendation over here.
My mistake....I generalised

Jim

 

[/align][/align]Too long to read probably .........but there it is anyway[/align][/align]JC[/align][/align]What speed should I drive to get maximum fuel efficiency?
[/align]This is actually a pretty complicated question. What you are asking is what constant speed will give the best mileage. We won't talk about stops and starts. We'll assume you are going on a very long highway trip and want to know what speed will give you the best mileage. We'll start by discussing how much power it takes to push the car down the road.
The power to push a car down the road varies with the speed the car is traveling. The power required follows an equation of the following form:
road load power = av + bv2 + cv3
The letter v represents the velocity of the car, and the letters a, b and c represent three different constants:
[ul][*]The a component comes mostly from the rolling resistance of the tires, and friction in the car's components, like drag from the brake pads, or friction in the wheel bearings.[*]The b component also comes from friction in components, and from the rolling resistance in the tires. But it also comes from the power used by the various pumps in the car.[*]The c component comes mostly from things that affect aerodynamic drag like the frontal area, drag coefficient and density of the air. [/ul]
These constants will be different for every car. But the bottom line is, if you double your speed, this equation says that you will increase the power required by much more than double. A hypothetical medium sized SUV that requires 20 horsepower at 50 mph might require 100 horsepower at 100 mph.
You can also see from the equation that if the velocity v is 0, the power required is also 0. If the velocity is very small then the power required is also very small. So you might be thinking that you would get the best mileage at a really slow speed like 1 mph.
But there is something going on in the engine that eliminates this theory. If your car is going 0 mph your engine is still running. Just to keep the cylinders moving and the various fans, pumps and generators running consumes a certain amount of fuel. And depending on how many accessories (such as headlights and air conditioning) you have running, your car will use even more fuel.
So even when the car is sitting still it uses quite a lot of fuel. Cars get the very worst mileage at 0 mph; they use gasoline but don't cover any miles. When you put the car in drive and start moving at say 1 mph, the car uses only a tiny bit more fuel, because the road load is very small at 1 mph. At this speed the car uses about the same amount of fuel, but it went 1 mile in an hour. This represents a dramatic increase in mileage. Now if the car goes 2 mph, again it uses only a tiny bit more fuel, but goes twice as far. The mileage almost doubled!
In effect the efficiency of the engine is improving. It uses a fixed amount of fuel to power itself and the accessories, and a variable amount of fuel depending on the power required to keep the car going at a given speed. So in terms of fuel used per mile, the faster the car goes, the better use we make of that fixed amount of fuel required.
This trend continues to a point. Eventually, that road load curve catches up with us. Once the speed gets up into the 40 mph range each 1 mph increase in speed represents a significant increase in power required. Eventually, the power required increases more than the efficiency of the engine improves. At this point the mileage starts dropping. Let's plug some speeds into our equation and see how a 1 mph increase from 2 to 3 mph compares with a 1 mph increase from 50 to 51 mph. To make things easy we'll assume a, b and c are all equal to 1.





Speed

Equation

Result


3 mph

3+32+33

39


2 mph

2+22+23

14



Power Increase

25


51 mph

51+512+513

135,303


50 mph

50+502+503

127,550



Power Increase

7,753
You can see that the increase in power required to go from 50 to 51 mph is much greater than to go from 2 to 3 mph.
So, for most cars, the "sweet spot" on the speedometer is in the range of 40-60 mph. Cars with a higher road load will reach the sweet spot at a lower speed. Some of the main factors that determine the road load of the car are:
[ul][*]Coefficient of drag. This is an indicator of how aerodynamic a car is due only to its shape. The most aerodynamic cars today have a drag coefficient that is about half that of some pickups and SUVs.[*]Frontal area. This depends mostly on the size of the car. Big SUVs have more than double the frontal area of some small cars.[*]Weight. This affects the amount of drag the tires put on the car. Big SUVs can weigh two to three times what the smallest cars weigh. [/ul]
In general, smaller, lighter, more aerodynamic cars will get their best mileage at higher speeds. Bigger, heavier, less aerodynamic vehicles will get their best mileage at lower speeds.
If you drive your car in the "sweet spot" you will get the best possible mileage for that car. If you go faster or slower, the mileage will get worse, but the closer you drive to the sweet spot the better mileage you will get. [/align]

 

Brillant!

 

You're right...too long a read! F that!

 

It'd be good for you Biggie.......help you to increase your word power...lol

Jim

 

Im with big on thisone, i read the fisrt line and then saw how long it was lol

 

Was a bit......wasn't it[&:]....lol
Took me 2 hours to do that write up as well!

Jim