GMC Envoy low gas mileage when towing

[karalyn]

I have a 2002 Envoy with Vortec 4.2 engine V6 and I was told I would have no problem towing an RV weighing about 4500 LB. I am only getting 7 MPG towing, and I get 18 MPG when NOT towing. Is this normal?
What is my towing capacity? I was told about 5700 lb but wondering if this is true. How can I find out for sure?

 

[Molson02536]

I have a 2002 Envoy with Vortec 4.2 engine V6 and I was told I would have no problem towing an RV weighing about 4500 LB. I am only getting 7 MPG towing, and I get 18 MPG when NOT towing. Is this normal?
What is my towing capacity? I was told about 5700 lb but wondering if this is true. How can I find out for sure?

The 4.2 litre inline six gives the Envoy a maximum towing capacity of 2812 kg (6200 lb.) for 4X4 models, and 2903 kg (6400 lb.) for 4X2 models.

The PCM could have been designed with a tow/haul mode and button, but alas it wasn't. Best one can do is choose a tune with tow modifications from a vendor like pcmforless.com, but unless you get flash software like EFILive, you can't change from one to the other quickly, much less on the fly.

It is a feature that raises the shift points and the pump pressure so the shifts are harder.. It does allow you to tow in od. But only after 65 mph and if your foot is not in it, It is a good system that gm should of put on the envoys and tb.

This should help you transmission, keep us posted. http://www.bmracing.com/PRODUCTS/Tr...ts/ShiftPlus-electronic-Shift-Improver-for-GM