View Full Version : MPG Question

04-15-2012, 12:45 PM
Hey guys.. I've been looking into 4th gen T/A's and Camaro's and got a nice deal in my hands right now... I've currently got a 5.3L truck with some mods that burns a full tank in about 1.5 weeks, making at least 4-5 trips everyday.. I'm looking at a 98 T/A with the following mods:

Ls6 Intake
LT headers w/ ory
Flowmaster muffler
Ported & Polished Throttle Body
Coolant line bypass
STP Lid & K&N Filter
Custom Grind XER Comp Cam 232/236 .595 .602 114Lsa with Spring kit from Texas Speed
New Timing Gear
3600 SS Yank Stall
Single Racetronix fuel pump kit thatís good for 550wrhp

Suspensions Mods:

UMI Sub-frame Connectors
Strut Tower Bar
BMR Adjustable Panhard Bar
BMR Fabrication Control Arm Relocation Bracket p# CAB002R
BMR Lower Control arms p# MTCA002
BMR Fabrication Xtreme Torque Arm p# TA001R
BMR Fabrication Rear Sway Bar p# SB003R
Lowering springs
New Shocks
New Struts

It has a set of NEW Primewell PZ900 BL 245/50R16 97W

I'm getting this for a sweet deal but I need to know if the gas mileage would be even any better than my truck? I am looking to DD it if I decide to get it..

04-15-2012, 01:36 PM
mpg is gonna be a little dependent on rear gears,which you didn't state what gear ratio it has.

04-15-2012, 02:07 PM
Check the gears.

Also depending on your driving style(passive/agressive) and if your in town driving the torque converter will kill your mpg real bad.

04-15-2012, 02:16 PM
I'm thinking about selling my car with similar mods an I am curious what they're asking for the car you're looking at. Btw I get around 23- 24 mpg. I had a z71 and my car gets much better mileage on the interstate but only 200 miles per tank in town.

04-15-2012, 02:37 PM
It's got stock gears.. He wants 7k for it Obo.. The interior and seat. We'd to be replaced so I might be able to get a lower price

01 CamaroSS SLP
04-15-2012, 03:57 PM
What kind of mileage do you get with your truck?

04-15-2012, 04:12 PM
Lasts me a week and a half driving 4-5 times a day to school and work and so forth

04-15-2012, 04:27 PM
Lasts me a week and a half driving 4-5 times a day to school and work and so forth

That doesn't tell us anything. Is your school ten miles from your house or 100? You need to tell us an actual mpg number to get a solid answer.

Anyway, chances are the T/A will get better mileage than the truck, but maybe not my much if you do mostly city type driving, as the converter will lose you mpg around town. On the highhway it locks up, so it won't have any effect on hwy mpg. Just keep in mind that economy cars these are not, but they'll be a heck of a lot more fun to drive than your truck.

FWIW, my '00 Formula A4 that's mostly stock with 2.73 gears gets bout 22.5mpg in my weekly drive, about 330miles a week with about a 70/30 highway/city split.

04-15-2012, 04:42 PM
A total of maybe 50-70 miles per day with lots of red lights

04-15-2012, 09:12 PM
If you're driving 4-5 times a week, driving 50-70 miles per day, and a tank of gas lasts you a week and a half, it sounds like you're easily getting a good bit over 300+ miles to a tank with the Sierra. That's most likely not going to happen with that Trans Am, especially with those mods. However, the car has a smaller fuel tank, like 14.5 gallons I believe, so it may actually get better MPG's, but the fuel will definitely not last as long as it does in your truck.

04-15-2012, 09:55 PM
You need to keep the truck. A cammed/stalled LS1 is not going to get anywhere near what you're getting in your truck if most of your driving is city roads with a lot of stop and go.

You didn't mention where or if the car was tuned. That has a lot to do with fuel economy. If you're cruising around on the highway with a 17.0 AR, you can get some pretty good mileage, but if it's 14.0 or fatter, you are going to be feeding the car pretty often. And with 93 octane instead of the 87 that you most likely run in your truck.

If you're basing your decision to buy the T/A on fuel economy alone, don't do it. If you were driving all highway miles and buying a 6-speed with just bolt'ons and a good tune, then I would recommend you buy the car. I have achieved 31mpg's in my old bolt'on, 6-speed T/A while interstate driving.

Starz T/A 17
04-15-2012, 11:20 PM
If your concerned with MPG's I would keep the truck or get a civic. LS1's in STOCK to NEAR STOCK form get great MPG's for what they are. But with the mods you listed in city driving I would say you would be lucky to get 15 MPG although highway will probable be low 20's. But alot there is going to depend how well the car is tuned. If your getting a really good deal on it you could always swap in a smaller cam and that would probable help, but honestly I wont say a 232 cam is too big for a DD because that all comes down to preference, but that is a really aggressive cam

04-16-2012, 11:26 AM
Just curious how many miles are on it? 7000 seems kinda cheap with all of those mods.

04-16-2012, 06:10 PM
It's got 126k miles on it.. Got some more pics and like I said dash and seat are f****ed, and the exterior could use some paint.. I'll keep looking for a car, haven't sold the truck yet so not in a rush