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**deevergote** · 03-14-2011, 10:51 AM

Bilsteins are fantastic shocks... so they're good to keep as long as they aren't blown. They're some of the very best you can buy for our cars.

If you install those Eibach springs, you might want to look into a camber kit, yes. Either way, you will definitely need an alignment after installation. If you don't get a camber kit, keep an eye on the inside of your tires, to be sure they're not wearing beyond safe limits. When the inside is bald, the tire is bald... no matter how much tread is on the rest of it.

The springs and shocks really shouldn't have affected gas mileage at all. Did you happen to add larger wheels, or sticky performance tires at the same time? That would have much more impact.
How's your tire wear? Did you have your wheels aligned after the new springs and shocks were put on? Having a bad alignment would essentially be dragging your tires along, causing resistance, and is likely to reduce mpg... I would think that if you had a shop install your suspension that they included an alignment in the process.

I would check into the DIY threads involving suspension installation on this site. It's actually very easy to do yourself. It was the first thing I learned how to do!

**DariuszZ** · 03-14-2011, 10:53 AM

Hey, welcome to cb7tuner!
first of all, ive never knew that lowering would decrease your gas mileage, therefore i cannot help you with that. I can tell you however that you will get about Front 1.2in and Rear 1.2in drop. This will give you a slight camber, and since you are all about "cost to minimum" you would have to get a camber kit (you dont want to change your tires every 2 months eh?).

Note:
You're getting 400 on a tank because the gas price went up and not because of new springs haha.

**deevergote** · 03-14-2011, 10:58 AM

How would the price of gas affect his miles per gallon?

If anything, I'd say mpg would go UP with expensive gas... because most people won't drive with a heavy foot when they're paying out the nose for fuel!

**GeoffM** · 03-14-2011, 11:05 AM

Are you noticing the change between winter and summer gas? Summer gas I can easily get 400 to a tank. At the peak of winter I'll see a steady decline.
400 - 360 - 360 - 340 - run out at 340 - 300. Haven't dropped below 300. I use my phone to track my mileage. With this warmer weather I've seen a 1.5 mpg increase!

**deevergote** · 03-14-2011, 11:11 AM

Cold air has more oxygen than warm air, which would technically explain the use of more gas in cold weather. The ECU sees more oxygen, and sends more fuel to compensate. This is really just a theory, and I have no hard evidence to back that up as far as the ECU programming goes (the air density thing is a fact, though.)

However, unless this guy drives like me (80,000 miles a year) this decrease in MPG has spanned multiple seasons... so that's not likely the problem.

Honestly, the MPG issue is very likely NOT related to the suspension at all, other than a possible wheel alignment issue.

**GeoffM** · 03-14-2011, 11:19 AM

Originally posted by deevergote View Post

Cold air has more oxygen than warm air, which would technically explain the use of more gas in cold weather. The ECU sees more oxygen, and sends more fuel to compensate. This is really just a theory, and I have no hard evidence to back that up as far as the ECU programming goes (the air density thing is a fact, though.)

However, unless this guy drives like me (80,000 miles a year) this decrease in MPG has spanned multiple seasons... so that's not likely the problem.

Honestly, the MPG issue is very likely NOT related to the suspension at all, other than a possible wheel alignment issue.

There is a switch over (at least in MI) from winter gas to summer gas, and air temp has an effect as well.
Also:

That was 2 years ago. The car has been solid since then. The new suspension rides just fine; the wheel gap has settled some but is still noticeable; and it's been getting a consistent 29MPG instead of the almost 36 it used to.

**deevergote** · 03-14-2011, 11:27 AM

Really? Wow, we've never had that down here. I guess in areas that get hit with colder winters, it's common. Our gas is the same year-round, unless I'm really that oblivious!
It seems that the OP is in roughly the same type of area, so summer/winter gas may be a reality for him as well.

**kevinswwi** · 03-14-2011, 11:46 AM

Thanks for all the replies.

Maybe I didn't make myself clear. The original suspension on this car lasted about 200K miles. Then I had the Bilsteins put on and a set of standard TRW springs. At that time (2 yrs. ago) the car was RAISED several inches. Car rides HIGHER than it was before. The wheel gap was (and still is) VERY NOTICEABLE. The car became less aerodynamic; hence the drop in fuel economy.

Been driving it that way ever since. Handles fine; rides fine. Wheel gap is still very noticeable but has 'settled down' some. Still have the Eibach springs; want to know if I can just have the TRW springs removed, install them, and will I still have a reliable car? Pretty sure the mileage will return, since I will be going from what seems to be well above the stock ride height (something funky with those springs I got) to an inch or so below. Just wanna get some idea of whether I'd be opening another can 'o worms by lowering it some using springs I had already bought a couple years ago or if I should get another brand of 'stock' springs. All I want is reliability and I want to get there as inexpensively as possible and IF possible I want my mileage back.

Thanks again guys.

**quaidum** · 03-14-2011, 11:59 AM

did the car get an alignment after the trw springs were put in

if your logic about the car being raised lowering your gas mileage is correct then that would mean that everyone who has lowered there car would get a significant raise in gas mileage, which i have never encountered

**kevinswwi** · 03-14-2011, 12:16 PM

Originally posted by quaidum View Post

did the car get an alignment after the trw springs were put in

if your logic about the car being raised lowering your gas mileage is correct then that would mean that everyone who has lowered there car would get a significant raise in gas mileage, which i have never encountered

The drag coefficient of the car was raised due to the raising of the suspension by several inches. I have seen it happen to other CB7's as well. I think some of the 'standard' aftermarket springs for this car significantly raise the vehicle. I have also seen some that don't.

**quaidum** · 03-14-2011, 12:27 PM

Originally posted by kevinswwi View Post

The drag coefficient of the car was raised due to the raising of the suspension by several inches. I have seen it happen to other CB7's as well. I think some of the 'standard' aftermarket springs for this car significantly raise the vehicle. I have also seen some that don't.

so with lowering the car you would see a raise in mpg's correct, but i have never witnessed this

not saying it isn't possible but i think more people would be like "hey i lowered my car now i get 5 mpg's more"

**HATCHing** · 03-14-2011, 01:16 PM

I agree with most reply above... but I believe your MPG loss might have something to do with your tires and wheel balancing.

Check your tires pressure
Make sure your wheels/tires are balance
All wheel alignments dial in
Make sure your wheels are perfectly round.. not dent from pot hole.
Make sure tires are perfectly round too, no bulge or uneven wear.

Make sure you do your regular maintenance..
oil change
sparkplug wire
sparkplug and gaping correctly
air filter
fuel filter
valve lash adjustment
check timing

**DariuszZ** · 03-14-2011, 01:23 PM

^ +1
I don't believe that your mpg would go up if your ride height is raised (although i know where your getting at; you driving against air, slower acceleration etc.) Keep in mind we're talking MAX 1in higher than stock. There is no way you would go from 500 to 400 because of this.

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