Excessive fuel consumptiom

[jonmac]

I have a VY ute, 3.8l that uses loads of fuel. Both petrol and gas. I average about 15l/100km and when towing 23l/100km. Auto trans drops into top gear at 125kmph. Is this a problem or would I better changing the diff??

[Calaber]

There are a few things to consider before just changing the diff.

First, what ratio is the current diff? I don't know what was fitted to the utes, but the VY's had a range of diffs, from 3.07, 3.46, 3.73, 3.91. The higher the number, the lower the diff ratio and the greater the number of revs for a given road speed.
Second, does it drop into top at that speed even with a light throttle? Have you had the trans serviced and what condition is it in?
Third, what type of LPG system do you have - the old fashined mixer type or far better injected system? The old single inlet set up can cause plenty of problems if it is out of tune.

[Sean880]

Apart from the gearing, when did you last change the engine air filter element? These clog up easily in normal use and you will use more fuel if running with a clogged air filter. I would be changing the filter at least every 12 months and possibly more depending on driving conditions you encounter in your area. The filters for the VYs are very cheap to buy and easy to install.

[jonmac]

Hi Calaber, Thanks for the reply. As I primarily use it as a tow vehicle it does very few k's per year. I'm not to sure of the diff ratio, but will endeavour to have it checked out. Also I don't think the trans has been serviced as its only done 75,000km. The gas injection was fitted in Adelaide from new, so I think it should be OK

[jonmac]

Thanks Sean880, Yes, you're probably right about the filter. I don't do many km's per year, but it can very dusty out here and I will change it and see if there's any great change. Thanks

[WogBoyz]

when was ur oil, spark plugs/leads, fuel filter changed last? make sure ur tyres are pumped up correctly

[jonmac]

ta WogBoyz, I'm having everything replaced late next week. Then we'll see if it's VY or a lemon!!

[jetboy]

Just my 2bobs worth , i have a vt it was using fuel like there was no tomorow i did everything leads , plugs , filters ect ect even took it to holden ,no one could fault it also had some power loss , this went on for ages . Anyway one day i was stuffin round lookin at shit an i noticed one of the battery terminals wernt looking that flash , so i shot down the auto shop an got two brand newys an threw em on , well blow me over it sorted out the damn car , heaps power again and ran on the smell of an oily rag . Just what happened to me .

[Damo69]

My VY commodore has a similar issue with fuel consumption..I'll checkout the air filter and battery terminals in the morning...

BTW this is my first post on here..woo hoo

[madcowbeavis]

In addition to frequent oil changes, ensure that the correct oil is actually being used. Recently one of my other commodores (i.e. not my main drive) dropped from ~12L/100km to ~9.5/100km's just from changing the brand and type of oil used. As the servicing had been done by myself over the past 2 years, I can confidently say that the only difference was the type of oil used.

[Mattrob]

What oil did you use that got the gains????