: V8 STS4 Gas Mileage - What are you getting?

02-19-09, 09:49 PM
Recently purchased an 07 1SG STS4 w/13k. Loving the car but the mileage isn't impressive. I'm getting about 20.5/highway (71mph) and 15.8/city driving. Thats mostly highway. 93octane

What are you seeing? Anyone seen any gains from the K&N in terms of mpg?

02-19-09, 09:58 PM
We have an 06 V8 1SG STS4. If I am not mistaken, our car has the 5 speed transmission while yours has the 6 speed transmission, so it may not be a direct comparison.

However, from my experience, your mileage numbers are pretty much in line with what we get. On a recent trip from Atlanta to Raleigh up I 85, we got around 21.5 MPG while running mostly between 80 and 90 MPH. With this car, I have come to think that anything above 20 MPG is bonus.

Ironically, the STS-V that we also have gets slightly worse mileage around town, but consistently gets around 22 MPG on the highway. Kind of funny since the STS-V is 469 HP. I chalk it up to the power loss due to the AWD system.

Bottom line is that I don't think your numbers are abnormal. Just enjoy the great power and the great traction that gets it all to the pavement!

02-19-09, 10:09 PM
I have the same year and model car you have (2007 STS4 V8) and get about 17MPG mixed. A little dissapointing, however, I bought my car new a little while back, and she still only has just a hair over 8,000 miles on it. So, hopefully she'll "get broken in". I'm also averaging about 280-310 miles per tank. On longer highway trips I'll get about 340-355 miles per tank.
Also, dhemric - How do you like your STS-V? How much "faster/stronger" is it then the regular 320HP V8?
I've never test driven one (my dealer NEVER has any V's on the lot, never mind the regular 320HP V8's lol). I was thinking of giving my 2007 STS4 to my mom as her primary car in a few years, and getting a nice used STS-V for myself. Is it worth it ? At 23 (well, 25 years old when I give my current car to my mom) I'm sure the insurance will be A LOT more then my regular V8. I'm seeing STS-V's practiaclly being given away on the "Bay". (I'd buy one Certified from my local Caddy dealer of course).
Sorry for rambling lol .

02-19-09, 11:02 PM
With a 2005 (5 spd), I have averaged 17.9 over 20,000 miles (using pencil and paper, not the car's computer, which is optimistic). Never broke 21 mpg over any one tank, including long trips.

02-20-09, 01:10 PM
Also, dhemric - How do you like your STS-V? How much "faster/stronger" is it then the regular 320HP V8?

I absolutely LOVE my STS-V! Having both cars, it is a really interesting comparison. For as similar as they are, they really feel like two very different cars when you drive them.

The interior on the STS-V is nicer as because it is all leather (similar to the Platinum edition interior on the regular STS).

The STS-V feels a LOT more nimble and moves like a much smaller car than it is and has LOADS of power. It is like driving a very luxurious Corvette. The ride is definitely stiffer than the STS4, but not unacceptably so. The STS4 is very powerful in it's own right, but since I drive the STS-V most of the time, I definitely notice that I don't have as much power under my foot when I switch off to the STS4. In daily driving, you don't notice it as much, but if you really get on it, you quickly find the acceleration limit of the STS4 whereas the STS-V just seems to keep on pulling harder and harder. It never ceases to amaze me how quickly and effortlessly the STS-V can get up to speed.

Mind you, the STS4 is no slouch when it comes to the power and handling departments, and I do like the adjustable magnetic shocks on the STS4. It just feels much heavier than the STS-V.

One thing I like about the STS4 is that is feels very "sure footed" when accelerating. With the STS-V, you are always aware that you can make the rear end get away from you (until traction control kicks in), but with the STS4, it feels like no matter how much gas you give it, all the power will get to the pavement.

There is really no way to directly compare the two because they are such different cars, but I will say that no matter which one you have, you have a darned good car. If you want to trade sure footedness and a softer ride for raw power, then definitely go for the STS-V.

Also, if you have the heads up display on your STS4, keep in mind that it wasn't available on the 06 and 07 STS-V. That is one thing I really like about the STS4 that I don't have on the STS-V and wish that I did.

02-20-09, 04:36 PM
Ya, my STS4 does not have the HUD. I wish I had it though.
Thanks for your input ! Now I REALLY want an STS-V lol

Caddy Man
02-20-09, 07:30 PM
I get really crappy gas mileage. Worse than I expected to get. I think out 2005 Jeep Grand Cherokee with the 4.7 liter V* gets better gas mileage than the STS4.

Can't beat the all weather capability and grip of the STS4 though.

Caddy Man
02-20-09, 07:31 PM
I get really crappy gas mileage. Worse than I expected to get. I think out 2005 Jeep Grand Cherokee with the 4.7 liter V8 gets better gas mileage than the STS4.

Can't beat the all weather capability and grip of the STS4 though.

02-20-09, 09:20 PM
I'm someone who likes to gun it. Highway cruising ya I get 20-21 mpg on my STS4, but city, stop and quick go off the line I'm getting 12.5-13.5mpg. Glad I work at home so I'm only filling my tank every few weeks

02-21-09, 05:46 PM
I can get 21MPG at 70MPH in my 2006 STS4 V8 1SG. I prefer to cruise faster and mileage rolls off fast due to the final gearing, IMHO. The wife's 2007 STS V8 1SE has gotten 25MPG at 80MPH all day and is nearly as hot under throttle. I feel AWD drag losses are balanced out nicely by its sure-footedness putting the power down. Neither benefit materially from higher octane fuels here in 87-octane RFG-gasahol-land.

Other cars we've owned (STS & Lincoln) have achieved higher MPG's with higher octanes and ethanol-free blends (Never as much as 10%) but we don't see that with the latest N*. No knocks or pings on SE Wisconsin's 87 octane under normal use. But our blend does sell for more than most since its only made in a few refineries. Well over $4 just a year ago. Wow!

02-28-09, 11:41 PM
Gas miles was the deciding factor for me when I purchased my RWD V8, I'm hitting well over 22 on the highway....