Hey, I'm new to the forum and figured this would be the place to go.
I just bought a used 2000 ZR2 a few weeks ago and now driving it for awhile realized the gas mileage is horrible. averaging 8-10mpg I know that cant be right, the blazer is pretty much stock with the exception on 32x10.5 tires. but that should be that big of a difference in mpg. and suggestions and or possible problems?

thanks, Will



hey, also to add:

where should my RPMs be running at?
like at different MPH. i havs a feeling its running too high.

 

at 70, u should be around 2000, with 3:42 gear and with bigger tires your odometer will not calculate mileage correctly. also bigger tires change the final drive ratio too

 

also....those big tires will slow your odometer down...the diameter is a lot bigger than the stock wheels, so the wheel is making less rotations but going the same distance if that makes sense to you.......so your gas mileage is probably right. have you not noticed your speedometer is off? Thats why your rpms seem off also, your engine is working just as it would with regular sized tires...... unless you just go off roading theres not a whole lot of reason to put tires like that on a truck...sounds like butt when you hit the interstate.

 

There are plenty of little tricks to buy yourself some gas milage. Search away. Look into a Cold Air Intake (CAI) for better MPGs, Seafoam (cleans crud out of your engine freeing up power so you dont have to get into the accelerator as much), Make sure your tires are properly inflated (noob move, but you'd be surprised), a grille guard/roof rack looks neato but causes resistance which eats more gas, might want to take a peek at your plugs (hell cap, rotor, wires etc. wouldn't hurt).

Search it up. In addition to the mpg threads, look into the tune up ones. If it frees up available power, it should translate to a bit of fuel economy gained as well.

Lastly and most importantly, drive like (thinks of a PC way to say this...) you're a responsible adult. Being the first off the line at every light impresses the ladies to no end. Also going 80 to work and whipping through traffic is much more efficient than waking up 4 minutes earlier. Sadly, those beat down your MPGs. Try to keep your tach < 2500 rpms. It sucks, but it will get you milage. You have to give a little to get a little

 

Lots of guys on the ZR2 forum are getting crap gas mileage.
Change your plugs, wires, dist cap and rotor. (ac delco platinum spark plugs, and don't cheap out on the wires)
Do a seafoam treatment through the brake booster and a half can in the oil about 100 miles before your next oil change.
And change the front and rear diff fluid

I'm running royal purple front and rear 75/90, and mobil 1 in the engine... I get about 14mpg city, and about 16-19 mpg highway, but I'm running the stock 31x10.50 R15 tires.

Also clean your MAF sensor with some MAF cleaner and check your air filter while your at it.

And one big thing that some people do, if your going along, don't press the pedal down any furter than you have to, if that little bit of extra is not helping, let it off.

I also cut some holes in my air box and added a drop in K&N filter, that helped with some of the low end issues I was having

 

something i found very interesting, i bought bosche platinum +4 plugs, Summit 8mm spiro-wound plug wires, MSD high-output coil, and Summit billet aluminum distributor on summitracing.com, and all but the dist. were CHEAPER than the replacement stock parts.....
but unfortunately still only averaging about 15mpg, still workin on mine as well...