Mileage sucks

#1 03-01-2003, 08:12 AM

Any ideas on how to improve the mileage of my '92 SVX? - other than a tune-up, overinflating the tires and keeping it in "D" instead of "3". I'm getting around 12-14 MPG, and with gas at around $2.00/gal, it sucks.

svxistentialist · #2 03-01-2003, 08:37 AM

Hi Franks

Haven't seen you post before, you are welcome on the board.

You have put your finger on the likely areas that would help. If your mileage is all stop-start, with no highway, it will stay bad.

I run my tyres 3-5 lbs over spec, this helps lower the rolling resistance.

Make sure you have a clean air filter, the easier it can breathe, the better the mixture.

If you are a city driver, stay using 3 rather than D. Trannies are lots more expensive than gas. But put it in D once over 50-60 on the expressway.

You get cold weather in NY. If you are using an additional tranny cooler, either in parallel or in series, this will probably overcool the tranny oil, and lose you 2-4 mpg in cold weather. You might consider putting in a valve that can close one of them off in cold weather. Alternatively, blocking off part or all of the airflow to the extra cooler is a time-honoured way of controlling temperature that is cheap and works.

Aircon. It is good in winter for defrosting. If you leave it on permanently, as I often do, it takes a lot of HP to drive that pump, so you will be losing another 2-4 mpg.

Get yourself a spray to clean up the throttle bodies, they gunge up depending on the quality of gas you are using.

Get yourself a fuel additive to clean the injectors. Do this with at least two consequetive full tanks.

Last call; the manual says if consumption is excessive, check the fuel pressure regulator. Replace if not correct.

Hope some of these can help.

Joe

PS Another to watch; Check your brake pistons in all four calipers. If they are not clean or the rubbers are damaged[cheap fix] the pistons stay onto the pads after you have let off the brakes. This causes drag causes consumption. Worth checking.

immortal_suby · #3 03-02-2003, 03:00 PM

Changing the pressure regulator looks pretty straightforward. Relieve fuel pressure, change part, done. Any tricks we should know on doing this -I'll be tackling this one soon.

floatingkiwi · #4 03-06-2003, 11:55 PM

"Get yourself a spray to clean up the throttle bodies, they gunge up depending on the quality of gas you are using"

Sorry about my possible ignorance, but isn't the gas put in at the injectors, way way after the throttle bodies??

svx_commuter · #5 03-07-2003, 10:56 AM

Hi Franks,

What kind of driving do you do? How long do you drive before you shut off the car and how many times do you start it during the day? If you are doing a lot of short trips many times a day your mileage may be that low. You do not have any warning lights on the dash light up?

John