Hi
bit of a puzzle can any one shed light on this. have a 1989 toyota dolphin motorhome not the fastest or most ecomical vehicle but drives well and attrachs a lot of postive atention. my issue is why i suddenly have a jump in performace. truck is due a service and avgerages 17mpg imperial should be about 20+ imperial mpg. spark plugs are light brown so not over fuelling oil level is on max for engine and auto box. wave my foot near throttle pedal and off she goes cruising at 50mph is impossiable without cruise control on.before 50mph was a struggle 60mph comes up far too quick with 3 ton gvw and aerodyamicd of a barn. what would cause this. im stumped.

 

Something in carb that was restricting it came loose...burned some carbon off the valves that wasnt letting them open all the way...

Something that was ignored before has righted itself. probably in the fuel system.

 

Could just be the difference between winter and summer gas.

I notice a difference.

 

The wind was blowing in the right direction.

 

I not sure but I feel I have to add. Did you put any stickers on the back window? I hear they add power.

 

Anyone steal your cat and was polite and stuck a test pipe back in?

 

Hi dropzone
no had cat removed 6 months ago. if a previous poster is right about summer fuel then it should be sold all year as current temps are around 0c.

 

Winter fuel is cheaper to make. It's crap, but they can only sell it in the winter (by law I believe). It's an emissions/profits thing. Summer gas is much better.